RAF levelling-

I invited 3 accounts from my main, giving me x4 accts with triple xp. If a friend pulls me through an instance, I get less xp because he's a 70 but it is still triple XP. If I start 3 new toons, and use one higher level toon from my main account, will the 3 lowbies get triple xp, or does the toon from the main account have to be in there at the same level?

Same scenario, except I use a high level from one of the invited accounts, and 3 lowbie toons, including main account, triple xp should definitely work, right?