I know that almost all grad schools make you send transcripts from every place where you received college credits. I have a bunch of AP credits that count towards my hours. My question is do I have to order AP score reports from ETS and send them to my schools, or the credits shown on my university transcript are sufficient?
You definitely do not have to. You could chose to, but I wouldn't bother since I'm 100% certain they don't give a crap. They probably don't even care that you have AP credits. They're really just interested in your physics work (yes, there are math and physics AP courses, but you'd have to take those courses anyway, so they don't really care if you took them as APs I'm sure).
Bottom line: don't bother sending your AP scores.