Uromastyx: healthy?

[Trollbie]

My sister in law has a Uro named sunshine. He seems healthy except a bit of stuck shed and what looks like stuck shed on his tail. I know nothing about them so I told her I'd post a thread on a forum to get expert advice. Here are some photos of sunshine. Does he look healthy?

Also she keeps him on millet seed. Is that a good substrate?







I apologize about the bad picture quality...