I have some conjecture on Louis Philippe II as to why he supported the Jacobins. I believe he thought that the ideas of the Jacobins and the revolution would lead to a constitutional monarchy with him as the head. How plausible do you think this motivation is? Honestly, I think his support of the Jacobins was not something that was consistent with his own self-interest without hoping to gain the throne.
It's hard to say. He might have been genuinely ideologically convinced of the need for a constitutional monarchy, whether or not that was going to result in him being the monarch. But there were aristocrats (like Mirabeau) who were behind the Jacobins despite not having any chance of becoming King themselves. The idea that Orleans wanted the throne for himself was a very common conspiracy theory at the time, especially among legitimists, some of whom believed the whole revolutionary movement was just a plot he initiated with the aim of becoming King!