I will try and clear the RAF a little.
For 3 accounts, first one has your main, and other two are linked with RAF. You can boost with a high level and the others get some benifits (3x exp, gifting to one toon, and 2 mounts)
With this same set up you can run 3 level 1 toons. Then you get the same and another toon gets gifted levels.
Doing it some other way, allows gifting to the refering account only (X ->A, X ->B) and two mounts on X account.