Your second point, on the other hand, I have to disagree with prima facie. The wizarding world in general has no problem taking idiots as leaders - look at Fudge. If anything, a stupid figurehead would be BETTER, because it would give Quirrelmort more control.

Fudge isn't particularly stupid, he's just not particularly smart. He occupies a position of nominal power with significantly more competent people maneuvering around him, so he looks dim by comparison.

A not-very-bright figurehead would probably be better than a very clever one, but a legitimate dimwit, someone significantly less intelligent than average, not merely about average, would be very unlikely to make it into high office.

It's possible that Voldemort faked the Godric's hollow scene, but I seriously doubt it; real or fake it took too much time and resources for too little return for me to think it's likely.