Valley of the Kings? I would put those above seeing the great pyramids TBH.
Seeing the pyramids and getting some photos there is a once-in-a-lifetime thing, but it doesn't take long to experience that. The Egyptian museum is cool, but most of the other stuff on your list just sounds like fluff to make it sound like you are doing a lot of different activities that all revolve around the pyramids.
Like others said, people will accost you if you wander within the crowds. Unfortunately, it's likely tough to cover up the fact that you are an American tourist so I'd stay with a trusted tour guide.
Scuba diving in the Red Sea out of Hurghada was awesome. My brother and I also snowboarded in an indoor snowboard park at the Mall of Egypt just to say we did. 🙂