Hi, I have 2 accounts with RAF right now and can explain when you will and will not receive xp.

IF YOU ARE TRYING TO LINK 5 ACCOUNTS WITH 1 LEVEL 70 AND 4 FRESH CHARACTERS THIS IS WHAT YOU NEED TO DO:

Do not have a SINGLE one of the accounts linked to the 70, it WILL NOT get xp. First off, anything over 60 ends up basically not having the full bonus of RAF, also your characters don't get 3x xp if their level is spread apart.

Account 1 (Level 70) should be unlinked.
Account 2 (Level 1) linked to account 3
Account 3 (Level 1) linked to account 4
Account 4 (level 1) linked to account 5
Account 5 (level1) also linked to account 4.

With this set up all of your level 1 characters will get triple exp. Voila! - Oh and a tip

If you are going to ding by turning in a quest: STOP. I'm not sure which but since it will seperate the levels of the characters they will not all get triple exp for turning in the quest. Only the first or the last.