That isn't how conspiracy to commit works. There has to have been foo (or an attempt at foo), and demonstrable knowledge of that act of foo (or highly probable knowledge), and actions to further the committing of foo (direct or indirect I believe). Just exploring stuff in the hypothetical is completely legal.

Only if you take real action towards committing foo. Talking about it does not constitute real action.

Conspiracy to commit foo generally means you are planing to commit foo, not talking about the best way to commit foo.