Please see the most recent updates in the "Where did the .com name go?" thread. Posts number 16 and 17.
1. I don't believe so
2. Yes, they are available on DVD from Flight1.
3. I don't think so, I installed UTX first, then GEX and it works fine.
4. Downloads will have all updates, but I don't know about DVDs. You can ask on the Flight1 forums, they'll be able to tell you.
http://www.flight1.com
Jim