1 No not afaik, but it can be bought cheap
2 I download them on another machine or you can disable windows update on win 7 (not on 10)
3 No my samples are on a normal HD too.
If you make a backup image of 10, you can install win7 64 pro and if I remember correctly it will work for 30 days without a key. Your win 10 key might work but I am not sure.
What is your audio card/device?