I think there might be a good argument that the citizens of Egypt were black; however their leaders could have very well been a different race entirely.
Nope, there are many colored illustrations. All, included slaves are light brown.
Except for Northern invaders (like Israelites), who are painted white and few imported African slaves.
Moreover, there are many descendants of Egyptians still living. The Copts are 100% descendants of ancient Egyptians, including using modern version of ancient Egyptian language, and even the Arabs are likely mostly descendants of ancient Egyptians.
Maybe.