#1: If he's from one of the veteran accounts, yes. If he's from another, non-related (to the RAF) account, and grouped with RAF-linked accounts, they will still get the 3x bonus. This is a bug that is planned to be fixed, no intended.

#2: Yes, if you immediately want mounts. If you don't care, you can upgrade online or with battlechests, etc. You just won't get your mounts for a few months.

#3: Correct, just remember you always have to play both veteran accounts to get everybody 3x.

#4-7: Right.