The extremely small teams (even by women's cycling standards where six is the norm) will have a dramatic effect I think, so the good will out earlier.
Barb, to your points:
1) yes, I think the result of the men's road race has changed my thoughts somewhat. Women's cycling only occasionally has races that include sustained climbs of the nature that we have here, with only a handful of genuinely mountainous stage races (Emakumeen Bira, Giro Rosa, Giro del Trentino) and no classics that are truly climbing-wise the equivalent of the Giro di Lombardia. Flèche is Flèche, obviously, and the Trofeo Binda is similar to Tre Valli Varesine, so these are often our best one-day races to use as guides, at least now Firenze is three years ago and the péloton has changed considerably since. The big thing from yesterday's men's race is that I am now terrified that Lizzie Armitstead comes right back into the list of favourites; I'd thought that since she's mostly known for explosivity and over punchy climbs she's almost untouchable, but has never shown anything over more sustained climbs like the Vista Chinesa that she would probably be dropped and have to chase on on the descent, now I'm less sure. Also Johansson, who is always competitive at the Emakumeen Bira but doesn't like the Giro, comes back up the list as well. Otherwise, much of the contenders remain as-you-were, Guarnier, Stevens, van der Breggen, Moolman-Pasio, Longo Borghini etc. - strong all-rounders and climbers, with wildcards like Lichtenberg and Niewiadoma, who are both great climbers but without a sprint option, and Ferrand-Prévot, the latter of whom's form is something of guesswork after spending much of the season preparing for MTB. I'm also now seeing some startlists which have Zabelinskaya on them after I thought she was excluded, if so she's a potential factor.
2) Some of the best descenders on the start list are Vos, Armitstead, Ferrand-Prévot, Neff (oh, she's an interesting wildcard as well, strong climber but lacking in pack skills, which may not be as bad in the reduced Olympic bunch). Some of the worst are Pooley, Stevens and the worst of them all - by a considerable margin - is Mara Abbott, however she does have the benefit of being almost certainly the best climber, though she prefers a longer, more consistent slope because she's not that explosive and needs the time/space to grind everyone to dust.
3) On paper Vos looks good but the Dutch have van der Breggen as plan A. Vos isn't at the level she was yet, certainly not, the other issue is that most of her 2016 calendar has not been especially hilly so we're not sure how she'll handle the big climb on the route; she did the Tour of California and was ok, and Thüringen where she was pretty good, but we can't point at Giro stages, MTFs or genuine climbing stages with serious obstacles in her calendar since comeback and say "look at that, Vos is back to her Giro winning climbing level".
Andy: is there a chance that climbers can get away? Certainly. The climbers turned the San Fior stage in the Giro into a highly selective one, and this is significantly more difficult than that was. Especially if some of the stronger-sprinting riders of puncheur capability start to drop (Armitstead, Vos) then the wick will absolutely have to be turned up because even those who have decent sprints left in the group are going to see their chances improved by being rid of them. A lot will depend on how the bunch is as it arrives at the bottom of that climb. The Americans will certainly have a lot to say as they have three different options for the win from there (Stevens, Abbott and most likely Guarnier), plus you have those climbers who aren't going to win a sprint (Niewiadoma once stating "it will never happen that I will win from a group, therefore the way to win is always by attacking" - I think she does herself down, from a group of her, van der Breggen, Lichtenberg and Abbott she would have a good chance!) - Stevens won three Giro stages of course, Lichtenberg was always there or thereabouts in the mountains, Abbott proved the strongest climber, Niewiadoma won Trentino on the MTF and tried to rescue her Giro with a 70km solo after one bad stage, Longo Borghini was the QOM, she only fell from contention due to one bad stage, and Guderzo has shown the kind of climbing strength in recent weeks I feared she'd lost.
Personally, I'm hoping for a hard race, and one where the climbers absolutely batter the Lizzies and Mariannes of the world out of contention on the Vista Chinesa, and we can see them descend hell for leather to try to make it. Plus of course you have the Clinic matters that would make an Armitstead victory an absolute PR disaster, no matter how much the press may try to strong-arm it into a redemption story. In an ideal world you get the pure climbers away playing games while the climbers with sprint capabilities like Guarnier and Moolman-Pasio have to chase leaving us with a finale open until the last.
Support squads will be key here; the deeper the squad the better protected the rider of course. As a result, the Netherlands and the USA are the ones in the best position, with quartets that have top-down strength. Ellen van Dijk and Kristin Armstrong are focusing on the TT so will probably do their jobs then pull out; the Dutch have, in Annemiek van Vleuten, a second engine that can provide massive power on the flat as well as climb sufficiently (although Annemiek protests she isn't a climber, she's top 10ed the Giro a couple of years ago, podiumed the Emakumeen Bira twice and won the Route de France), while if Vos is feeling good, having Anna VDB as an engine is a luxury not afforded many; once Kristin has done her bit however, the Americans will have to think about whether they spend Evie Stevie, as she's a significantly stronger TT engine than Guarnier or Abbott. Italy have four but I'm really not sure how they're going to play it with the riders they have; Bronzini is durable, and has massively improved her climbing over the last few years with this race in mind, but it's surely too tough for her; Cecchini could contend from a small group and won Thüringen so is on form but the climb is likely to be too sustained for her too; Guderzo is the strongest TT engine but they might not want to waste her on the flat, and ELB is their best chance of the win.
Australia's best option is probably Amanda Spratt, though Rachel Neylan has a track record of good placements in hillier Worlds courses. The absence of Tiffany Cromwell is a head-scratcher, except that of course their whole squad rides for Orica. Germany will probably use Brennauer and Kasper on the flat, then leave Worrack and Lichtenberg to their own devices from there on in; Lichtenberg is used to being isolated in the more mountainous races and performs strongly so this shouldn't cause too much consternation for her, however due to her abject sprint she's an outside bet at most for a medal, sadly (I'm a big Claudia fan). Canada are a very interesting potential wildcard. Tara Whitten will probably be used for the TT, but she's only raced in North America most of the year so I haven't seen much of her. On the other hand Karol-Ann Canuel has been climbing very well, and Leah Kirchmann was top 10 of the Giro, has a good sprint on her and is a decent functional climber; this might be too much for her but if she's in the first group back and it comes back together on the run-in she's absolutely a dark horse for even the Gold. Poland's team are all combative, Plichta is aggressive but not likely to be strong enough against the absolute elites, Jasińska is regularly on the move late on in almost any high profile race and Niewiadoma is an outside candidate as a strong climber - she's won difficult hilly and mountainous races this year (Elsy Jacobs and the Giro del Trentino) and isn't the type of rider to die wondering; if she has the legs to attack she will. Also with only three riders, Great Britain are all in for Armitstead (when Pooley announced her plans to return, the first thing in the press was that they had another strong engine to work for Armitstead, giving her the freedom to fight for her own goals in the road race was never even considered). Harris has good rapport with Lizzie and has acquitted herself very well on the road, she'll probably be there to pilotfish the earlier part of the race. Sweden have three riders and Fahlin was pretty good at Thüringen, but it's going to be all about Emma J, and for the most part she will try to bury herself to mask her lack of protection, then try to make moves late on, finish 2nd or 3rd if she does make the decisive move (that's kind of her thing).
France have just two, Cordon is one of the most selfless domestiques in the péloton and an excellent engine (quote: "it's better to be a perfect teammate than a bad leader"), the big question will be what PFP's road level is, as since April she's only done the national championships (which were won by 49yo Edwige Pitel, first time Pauline's lost in years) and La Course, which is worth so much less than nothing as a form guide for the Olympics. She's going to have at least some climbing legs owing to MTB training, then again she has also been plagued by bad luck this year and is powered by righteous indignation following the recent public spat with Lizzie - however if the MTB is her focal point she may not be on the same form as those for whom this is the all important day. South Africa also have two, though literally all their points were won by Ash so she's the obvious leader. She was 6th in Thüringen and is a very strong climber, she'll also be used to riding at a numbers disadvantage as she's on one of the smallest teams in the pro field, and is an outside candidate for the win here. The last 'team' is Luxembourg, with Hoffmann and Majerus; both strong riders for reduced sprints but neither I think will be strong enough to go from the group here, they'd need a lead over the field at the base of the climb to compete.
Then you have the riders flying solo, of whom the immediate name that jumps out is Alena Amialiusik (though it's a shame the cut-off date means Kseniya Tuhai didn't qualify an additional rider at the Giro after her excellent climbing performances), who won the European Games RR last year on a hilly course. She finished in the top 10 of the Giro and has been one of the bunch's best for a few years now, working alone is obviously going to disadvantage her but she has a chance of making at least a selection. Ditto to a lesser extent Solovey, though with her history and that she'll probably be focusing on the TT it might not be ideal for her. She's not had much racing either, but that's not stopped her emerging strongly at major championships in the past. As I previously mentioned, Jolanda Neff is a wildcard and won the very mountainous Tour de Pologne recently, but that was quite a weak field and with no helpers and no sprint, and that she'll be focusing on the MTB race a few days later, she's an outsider only. Also, nobody has won more races in 2016 than Cuba's Arlenis Sierra, but the level of those Central American road races that make up most of those (she also won the Tour de Brétagne) is unclear. Lower down the list of solo candidates, Vita Heine is aggressive but this is too mountainous I think, Flavia Oliveira is a very experienced rider and a strong climber (2015 Giro QOM) on home soil but after a disagreement between her national authorities and her trade team she hasn't had a particularly cohesive season, often working on a 'have licence will race' basis as a mercenary all over the place. Olena Pavlukhina has had a very strong season for BTC, and Polona Bagatelj is a good climber, however I think not strong enough to make the selection if the pace is really forced on Vista Chinesa, especially as she's got no support. And finally there's that huge question mark over Olga Z.