Yes. Obviously if the mere thought of possibly having to live out for a year fills you with terror (although it's worth bearing in mind that the majority of people who actually do it think it's great), you can rule out colleges which can't
guarantee you college accommodation for three years. Other than that, though, you'll have very little choice over which accommodation you'll end up in, so I don't think there's really much point in looking at pictures of rooms and deciding that St Anne's has *the* perfect room for you, when there's a strong chance that even if you get in, you either won't be at St Anne's or that you won't be put in that particular room if you are.
I think there's a guide on the wiki somewhere. But really, you need to be aware that at the end of the day, all the criteria on the basis of which you can pick a college are quite arbitrary and superficial. The most important factors in whether you'll actually end up being happy at your college are the ones you
can't influence (i.e. the people you meet, whether you get on well with your tutors, how well you're coping with the workload, the sports you decide to do). Of course you have to make an initial choice somehow, so you may as well go with arbitrary stuff like college size, location, what the rooms look like on the website, age, number of letters in the college name, etc, but I wouldn't take the whole thing
too seriously if I were you. Most people do end up liking their colleges, even if it's not what they originally had in mind.
I can't see anything obviously wrong with it, if that's what you mean.
Erm, I think you may be getting a wee bit paranoid there.

Most people aren't used to writing two essays a week when they come to Oxford, but you get the hang of it after a while. If your grammar is truly atrocious, tutors may have an issue with that and refer you to style manuals, or whatever. But if it's just a matter of using a dodgy construction every once in a while, they're not going to be terribly fussed (although they may still point out glaring mistakes so you'll be able to correct them).
You're not actually being serious here, are you?

TSR is
an internet forum.
All internet forums are full of people picking on each other's sloppy grammar.
Anyway, if you're genuinely worried: no, bullying people for having poor grammar skills isn't really the done thing here (or anywhere else for that matter) and you'd have to be extraordinarily unlucky to encounter people who actually do that in real life. None of your fellow students will even know what you write like, except for your tute partner, perhaps.