As far as the android phones go, I've tested several that individuals in my office have. The Droid X seems to be about the best currently for speed that I've tried. I personally have an Iphone, but my next will definitely be an Android based phone if possible.
1. I'm a compulsive list maker. groceries, things to buy, things to sell, etc. - Never a problem with the droid phones.
2. compact camera - Takes really good photos, better than my Iphone.
3. star-gazing app - That actually requires the 3G network, wont work on wireless. Still, the app is VERY cool.
5. Skype or Google voice through wi-fi - Will also work very well. Plus, the Android version allows for video with it.
6. If I understand correctly, any cell phone can be used to call 911, service plan or not. - Correct on all cell phones. They just don't do location services, but 911 always works.