My other big question is how this interacts with monetary policy. Inflation tends to preference financial capital by a.) lowering the real cost of outside credit and b.) causing dislocations within the economy that create opportunities for new startups. That could offset higher corporate taxes to some extent, while if combined with low corporate taxes it could spark a mania.

I don't see this holding true. Can you explain how?

Like, yes as a personal investor you now have less to invest, because you are taxed more on your income. But of the money you have left after tax, investment is still investment. There's no other way to make money of your money then to invest it. So as long as you don't spend all the money immediately, the incentive to invest it is there.

Also, the companies you invest in will be incentivized to reinvest in themselves, thus their stock growth potential will be higher, so a good time to invest in them.

Finally, the biggest investors arn't individuals, but investment firms, and because they themselves are a company, they themselves are like all others more incentivized to reinvest into their business, thus they are more likely to want to take their profit and invest it some more, instead of cashing it out as revenue.