Let me take your questions in order:
1) Yes, people are running Android 2.2 there was a leak of it about 3 weeks ago and there are quite a few stable ROMs based off of it.
2) Yes, you need to be rooted.
3) As long as you follow the instructions to root your phone there are very few risks, I have not heard of anyone bricking their Droid doing it.
4) Yes you need a computer
5) Froyo is Google's codename for Android 2.2
6) The OTA update for the Droid has not been sent out, so no it is not officially out for the Droid, only a few Nexus users got an official OTA update.
7) Flash is out and can be put onto a rooted droid running a Froyo/Android 2.2 ROM. I have it on mine and it works quite well.