Engineer the syntax to succinctly address the material and you can cover it well with 3,000 words. It comes down to word choices and phrasing, but you can do it! I can tell by the way you write, that will do it justice with a minimal compromise.

Absolutely you are doing too much. A 3k word essay typically should answer 1 research question, not summarize all of political theory.

I find doing a ten minute meditation before working on essays really helps me. A clear head is a good place to start.

Yes.