[finalgrunt]

Hi and welcome.

As long as your pet deals less than 50% dmg your group won't experience the xp penalty. You shouldn't have any issue outdamaging the pet with the two of you.

As for leveling up ... it's a matter of taste. One could always sell / buy for the other anyway. Go to wherever it seems to the most fun to you both below level 20, as you'll end up in the hot zones soon enough.

P.S: send me a tell ingame for a quick buff / port.