To anyone else thinking about a tool - I've fizzled out before with a wiki because of endless tool hunting. If that's happening to you, I'd honestly say just start with plain text (maybe markdown) - just make sure you can write your ideas somewhere. Then progressively enhance.
(never asked questions)
- Does anyone else keep their own knowledge wiki?
- Some discussion of knowledge management in org-mode: Serious knowledge management / concept networks with Org-mode? : emacs