No you can't, because you will have city codes that will need it below 8-16." It'll depend on the type of conduit or wire you will be using. Cement slab could be on top after.
Mold should be cleaned/killed first as best as you can with bleach or related product. Walls should then be prepped if needed, and either primed/sealed, then painted. You can use a masonary paint but it'll depend on how much paint is still on the walls. A latex paint is useable too. If mold is...