Don't you find Olaf resurrected as a Draugr? He probs worshipped Alduin.
Maybe, but maybe not. You find a lot of people as Draugr, even if they're from periods long after Alduin's defeat. Potema's catacombs are filled with Draugr, and that was probably built in the Third Era. I know Olaf is in the First Era, so he might have. I don't think anyone worshipping dragons would have the guts to try and capture one.