My wishlist for trait options would include the following:
Changing yields of improvements (like +1 food from farms, +1 hammers from workshop, etc. I'm picturing an Egypt with one trait called Power of the Nile, which increases wonder speed, farm production improved, etc., a workshop for England is more productive, etc.)
Reducing war weariness
Changing yields from buildings (like in the awesome civics mod, only trait linked not civic linked).
Worker speed changes
IF it's possible, a trait that builds roads faster OR let's you regard terrain like a road (like in Civ V).
Stuff like that