If you have linked your accounts wrong, there's the possibility to call blizzard and let them reset up the Raf linking.

I have f***ed up my raf in the past too, so just called blizzard to change the linking, they made no problem of it and they were pretty exiting about multiboxing!

If you have linked account 2,3,4,5 all to account 1, then yes all of the levels you like to grant will be granted to account 1.

Keep in mind, when you link all accounts to account 1, you will not be able to boost with accounts 2,3,4,5 and have the raf bonus of 3x exp