Ok, so my fellow GM is poring over the module for thoughts and preparation.
First thing's first: Eldritch Blast. The Red Wizards have it, but there's no description of it anywhere. I saw on dndclassics.com someone suggested using 1d8+Int damage for this cantrip.
Second item: No/Few Magic Weapons. And lots of resistance/immunity to mundane weapons. It's gonna be fun to be a fighter!