The uvula is the little "punching bag" you see at the start of the throat, and, yes, it can and has been pierced. At first, it was extremely rare, but these days, it's been done by hundreds of piercers.
I would imagine that would take some getting used to. The ball looks fine but wouldn't something dangling like hoops activate the gag reflex?
ew, gross. i can't imagine someone clamping my uvula and then shoving a fucking needle through it! and then having shit in my throat all day? the fuck ever.