I do think Elon is not being very rational buying Twitter. It's a toy and he can afford to buy it.
The second point is not really a valid criticism. That launch was a demonstration launch of their heavy booster variant. Rocket companies never launch commercial payloads on experimental rockets. When testing the rocket, they need to test it with some test mass. They can be (and usually are) boring and launch a block of concrete. Musk saw it as a clever marketing opportunity and launched a car. Much of Musk's success is inspiring bright people to work for his companies, and that explains a lot of the publicity stunts he engages in.