In the past, which may not be indicative of things today, I was able to freely move Warcraft accounts both onto fewer B.Net accounts to consolidate onto a single account and then to split them to two five B.Net accounts for the purpose of RAF'ing five more accounts for ten in total.

The brand new accounts had the same mounts as the existing accounts.
Each of my original five had individually earnt their special mounts.
So each pair of accounts had one account with each mount on their own merits.
If you had only earnt a mount on one account, put them onto a B.Net and then moved them off of that B.Net, I'm not sure you would retain special mounts on accounts who only had the mount because they were with an account that had earnt it.



In regards to the RAF.

If you were to only move one established account to a new server.
And then run your own RAF.

Call that account A.
I'd do two chains from A.
A > B > C
A > D > E

You could boost several sets with A.
And because you have at least two accounts that are linked from A.
They can combine to grant levels to a new toon of the same class on A.

So if your booster boosts 4x Mages.
And you have at least two accounts linked to the parent account.
Then one level-grants a Mage on the booster account to half the boosted level.
And the other level grants that Mage, on the booster account, to the level of the boosted characters.

Depending on how many teams you want to have...
You might benefit from each account linked directly from the account A.
A > B
A > C
A > D
A > E

That would give you two granted characters, on the parent account A, per one team boosted on BCDE.
Also, if time was more important than cash, you could potentially transfer an entire team (of extra boosted characters) from A to BCDE.