I have never fed my cham a mealworm.
Too many problems involved.
Zophoba worms, however, are fantastic feeders.
At this age I was feeding mostly crickets and some waxworms. I know everyone warns about waxworms and their high fat content, but when you're feeding a baby 5 or 6 a week, I don't think it's such a big deal.
Phoenix worms are hard to digest unless you pierce them with a pin before feeding (they are high in Calcium). I think fruitflies are a waste of time at this stage.
One of the main reasons for offering a variety of feeders is that chameleons get bored. However, this doesn't really happen until they're quite a bit older.
So, I wouldn't really worry so much about variety early on, just concentrate on a good gut-load for the crickets.
-Brad