As Trevor says, AIM is not part of the core of Android. I'm sure that there are a variety of IM apps available, but I haven't looked.

I've never encountered any app under Android that required a particular type of connection. I'm not saying you're wrong; I'm just saying that's really odd.

Battery life is obviously very hardware specific, but I find that the two things that kill the battery the most are the GPS and the display. Since you're doing initial playing with it, you're probably using both of those more than you're likely to in "real" use. That said, I definitely have to charge my N1 every night, and if I use it a lot during the day, I might fail to get 15 hours out of it.

I'm not sure what you're saying about the button placement. I don't think I've ever accidentally hit one of the buttons while typing.

I've not noticed that the unchecked checkbox ever looks checked to me, though I understand what you mean. That's just the default checkbox widget.

There's currently no way to acquire screenshots without attaching the phone to your computer and using the SDK. Google cites security as the reason for this, which sounds lame to me.