I'd say, for the most part, that everything above is true... more or less.
As for the elitism, I would definitely say it's true. In part, it's well-deserved and justifiable. The fact is that it's the best SUNY school - most selective and most intillectually challenging, considered New York's Public Honor's College. On the other hand, there are an awful lot of not-super-intelligent people at SUNY Geneseo. This will happen at any "highly selective" college, but the reality of the matter is just because someone gets good grades in high school does not mean they are smart, and certainly does not give them the right to be elitist. Alas, for all of the high-and-mighty, "Harvard - for all of those who couldn't get into Geneseo" t-shirt wearing, self-absorbed d-bags at Geneseo, there is a roughly equal amount of down-to-earth *actually* intelligent people.
Lack of diversity... Yes. Plain and simple. Not only from a racial standpoint, but also geographically and socioeconomically. The majority of students at SUNY Geneseo, it seems, are middle-class white folks from (in approximated order of prevalence): 1) Rochester, 2) Buffalo, 3) Long Island. Not many out-of-staters... But that's just the way the SUNY system seems to work (even thought Geneseo is consistently rated among the best valued colleges for out-of-state students). That said, if you don't fit into one of those categories, that's no reason to shy away from applying to Geneseo. It just seems to be the luck of the draw that creates that lack of diversity. I think the school has made significant efforts, at least in recent years, to change its culturally-homogenous image. There are a number of different cultural and racial clubs/groups on campus and there are consistently activities in the student union and throughout campus that emphasize diversity.
Party school... Yes and no. Frat parties? They're a dime a dozen. And they suck, badly. But outside of them, at least prior to Junior year (when you can move off-campus) there's not much. As a freshman and sophomore, expect that your only method of imbibement will be paying $5 for a night of Keystone Light from a keg in a dirty basement filled with testosterone-ridden meatheads and speaker-rattlingly awful music. Once you can get your own place, though, and your friends do the same... A world of opportunity for *good* parties becomes possible. That said, if you don't like partying, you don't have to. Over the years I've met a ton of perfectly happy people who swear against drinking, and have never been to a frat party. As with most schools, there are plenty of late-night activities beyond the realm of partying in the student union and elsewhere.
Female-male ratio. True.. becoming less-so (I think). Doesn't really matter. There are an awful lot of good looking women on campus, though. That is for sure. I'm sure that's true at any college though.