Thanks for the good ideas.
So far, I think I will add 4 levels of sorcerer to him. That gives him access to:
0) Ghost Sound, Arcane Mark, Prestidigitation, Mage Hand, Open/Close, Light
1) Erase, Reduce Person, Ventriloquism
2) Arcane Lock
He will start off invisible, cast Ventril., then Dancing Lights and Ghost Sound as a distraction. As defense, he has the arrows, Otto's, and entangle.
For jokes, he can create images, Arcane Marks, arcane locks, erase, and reduce person. I like replacing a weapon with a trout, that sounds hilarious.
The cleric is probably going to Dispel Invisibility, so the one Dispel Magic might not be enough for him to stay hidden.
Any good ideas for tests of the PCs greediness? I think that is the best way to have him interact with this specific group of players.