I agree with Grrawr...mites should rub off with that Q-tip, & they move. I've not had any lizards with mites (I'm mostly a snake-keeper anyway) but if crickets have
been left in cage with that gecko, like more than he can eat, they will possibly go after the gecko, especially if there's nothing in the cage for them to eat besides.
So I agree, little red dots might be insect bites, or some other kind of irritation.
Pics aren't close enough for me to see either...