The high level + 2 low level linked character boosting topic has been tenatively answered by Syndri

Going back to this:

Q u o t e:
Question #1:

Account1: lvl 70
Account2: lvl1
Account3: lvl1

Account2 recruits Account3. Account1 groups with 2 and 3, running them through low level instances. Do 2 and 3 get increased XP? The wording of the faq says the mobs must not be grey to the invitee nor the invited, but does not mention whether an unrelated 3rd person of much higher level will break the xp gain.



Present response: Experience would be mitigated by the presence of a higher level character; however, the mitigated experience would be tripled due to the link. Remember, if one of the linked characters is lower than the other, only the lower level one will receive the XP boost.

This is being tested currently. If the response changes, I'll let you know.