1. Start --> Run --> Secpol.msc. Click OK. Drill down to Local Policies, Security Options. "Disable" all the User Account Control items shown.
2. My understanding is that this isn't enabled yet but will be in future builds. I could be wrong, so please second-guess me
3. There are some threads in the neowin.net/forum Vista Beta sub-forum about this. Also Microsoft today released the specs for what a "Vista Premium Ready" machine will have. Also see: http://arstechnica.com/news.ars/post/20060614-7060.html
4. Sorry, not entirely sure why both were included, maybe for plug-in compatibility?