If fast Auto Focus Live View is important, there is no other choice, besides A300/A350. If you're looking for the absolute best picture quality (in the same price range), look to Canon or Nikon. I have an a350 and love it. In reality, none of the 3 companies make bad DSLRs, they all shoot good enough for "normal" people.
Don't know about the D60 but A300 has been very easy to use and learn. It also has very good features. I once used a D40 and it was a lot more confusing. It's your choice but I'd choose A300.
Don't remember... For the "fireworks" I used a long exposure time and a high ISO. The fire was shot also with high ISO but the exposure time was like 1/250 second.
You shouldn't buy a200 for a few reasons.. It doesn't have live view and the canon 1000D costs the same amount of money and it's better. You should check what you want from your camera and then think again :)
I had a big glass bowl of water and lots of lights around it. Then really short time to the opening (don't know the name). Then just dropped the fuits there and tried to time the shot right :D