If you have 2 different bnet accounts in the name of John Rambo you are fine when you multibox a toon of each account together.
If you have 2 different bnet accounts, one named John Rambo and the other one Rocky Balboa, and you group them up to multibox, then you are violating the ToS.

So put your raf accounts on the same bnet or on a new bnet with the same info as your original, and you should be fine.

As far as updating your bnet account name: that happens only in very specific situations, and most of the time they will refuse to do so, as it would be an incentive for selling accounts. A specific situation could be that someone made a bnet account with a dummy name (good internet practice in general), then buys some licences, keeps playing that account for years from the same IP and all in a sudden you need to call blizzard and the rep guy sees that 'zenga the bastard' is not a real name. In which case they will ask for info like CD keys, etc ... and you'll need to provide an ID. Long story short, your best bet is to call them and explain the situation, but you'll need a damn good reason and be able to back it up.