Could you peel the eggplant first before marinating and grilling?

Hi there! Nea agrees with Nancy's suggestion to use a vegetable peeler. She says: "Yes! You can although I’d recommend leaving it on to help keep the eggplant slice together. Use a vegetable peeler to peel it!"

Yes, you could - use a vegetable peeler or a paring knife.
The younger and smaller the eggplant, the skin is fine to leave on.
The older and bigger the eggplant, there is more chance the skin will have slightly bitter taste.