2) Also, that seems like something which would make more money for someone else, which does not fit with my model of Trump's behavior.
The SEC is irrelevant if there's no specific law against it, never mind that there's no evidence anyone can prosecute for anything even if it was a crime.
As far as making money for someone else, doing a "friend" a favor is not the same thing as charity, nor is laundering money through a proxy. If you hypothetically give away a trillion dollars without receiving anything in return formally that doesn't mean you haven't bought something. Ownership is only the convention that other people think you own something, backed up by some sort of written records somewhere.