GF pizza is very safe, prepared and cooked in separate dedicated areas. They even go so far as to leave foil under the pizza, and leave it uncut to avoid CC.
That being said, the GF pizza crust really sucks. It's mushy, floppy, and depressingly thin compared to the real thing. If you order from them you really have to ask for it well-done to crisp it up. Even then, though, the taste leaves a lot to be desired and for the price you don't really get a lot. Don't expect leftovers.
— Very
— Gluten-free items are marked on the main menu
— Not Much
— Below Average