I mean I already submitted it on July 4th and it hasn't been verified yet. so should I just wait until it's verified or can I add more schools right now?
If you re-submit your application to add additional medical schools or additional letters it will NOT affect the verification time. Your application will remain "in line" and not be bumped due to these additions.
Seconded that it will not affect your place in line at all. I called them to confirm and you can do the same if you're worried (you just have to wait on the line a bit).