[avmich]

Second question is very delicate. You definitely don't want to discuss something which may end up being unattainable. Say, you're working on a new physics, and you don't have something to show in form of math theories or experiments. Chances are you'll be labelled a nut, which from a nerd community could be counterproductive (see "ought to work on a good ides which looks like a bad one"). So you want to germinate your ideas - and perhaps throw those not good enough - until you have a sort of MVP. Which defeats the idea of the second questions substantially.

If you have something to show, it's more in venue of incremental, predictable work, and less in "out there" ideas perhaps.