1: Not that I've seen, at all, ever.Not the YouTube ads, but (1) being paid directly or more likely through third party by the manufacturers and, more important (2) have access to new vehicles to have something, anything, to show on YouTube.
2: Yep, that's true. That's a form of compensation, and a very real one. You can see that play out via the coverage of preview/pre-release vehicles, and how carefully they all toe the line on embargoes.
But the extent to which many of them praise Tesla about some things and yet still complain about no buttons tends to tell me they're not being bought in the sense that was implied.