1. Both are stable, Rockcheap and Amlogic
2. Yes, but just not much from the features released by google
3. two USb is normally ok for you. not so many USB devices you can plug except USB storage. To PC USB no use, nobody connect to PC via USB, especially your box is put near your TV
4. 3.x is buggy, need to be upgradable to 4.0, but don't know who can and when
5. If you can find the real supplier and get support, then it is safe, if not, you will lose the OS upgrade or bug fix upgrade support
6. Look at the review above, ATV1000 is quite stable and ATV4000 is interestign
7. Which one? any link?