Ok so make this clear, I am a rear admiral and my friend is LTC, can he come with me to do my missions? Will he get my exp points (amount) or he will just get low amount of EXP points?
Yeah, it really makes more sense for you to match HIS level than the other way around. He would get XP for the kills, but no mission rewards, and reward XP is reduced. Plus, he will be way underpowered doing your missions. Sort of like how LtC are leveled up to 45 for the borg red alerts. Yeah, they have more hit points, but they can't kill anything.
EDIT: I mean its better for you to do HIS missions than him doing yours.