I can't remember if I read this in a fic somewhere, but I've got it fixed in my brain that Ollivander is strictly neutral, that he'll sell a wand to anyone.

He strikes me as rather shady, actually.

I don't think that the wands are registered. Or even traced, else why doesn't Hagrid get in trouble for using his?

OTOH, if they were all registered and traced and all, it wouldn't surprise me. The MoM, and really, the wizarding world in general is fucking creepy.