I'm not talking near term, but lets assume we do get a space elevator to work within the next 100 years. Is is so far fetched to put up dual purpose solar power satellites that both reflect heat and beam down power? In the far future could it be possible to terraform venus to some extent by having floating space colonies that also blanket orbit with solar power reflectors?

I think many things are possible if we can ever figure out how to get mass very cheaply into orbit. Then we can start to exploit space resources like asteroids, and bootstrap some amazing space structures.

If we humans are going to continue to grow population, only technological advances will enable it without crashing our ecologies. Otherwise, we better start doing a better job of birth control. Of course there is always the natural solution, ....ecological disaster, famine, plague, and war to winnow population like it has periodically for the history of man.