Any question answered...

No, the rim has a centre bore and the hub has a matching shoulder to centre the rim on the hub. In modern manufacturing, the bolt circle is pretty accurately concentric with the centre bore, and the small amount of slack is taken up by having everything flex a bit, because the world is made of rubber.

That's not always the case. Quite a few wheels centre on the studs/bolts. Old 3-stud Citroen, wide-5 VW, wide-5 Ford, early Ford wires, 60s Ford 4 just to name a few that I'm familiar with.