Wrong on every account, Bubbadad. If you are looking to grant levels to your main account, tying all 4 to your main account is best. With the way the reward system works, you could get all mounts on your main account with the single invite and use them on all the RAF accounts, too. Your main account would also get 4 free months of game time when you purchase months on the other accounts. It's already been pointed out, but most legit multi-boxers have all accounts under a single b.net
If you're paranoid about Blizzard tying the accounts together, then you're going to have to do a lot more work to secure the accounts. You'll have to buy each key separately, with separate billing details and separate names or Blizz would already be able to link the accounts. They'd also still be able to see where the RAF invites came from, once again linking the accounts. If you ever get hacked and have to verify the account, you're screwed again because you can't provide picture ID to verify the account.
In fact, the only advantage in chaining the invites these days is that you can summon all party members. Not really a big deal.
What I'm trying to say is that recruiting all the accounts from one single account has much better benefits than chaining invites.