[BigV]

Third question first:

Context matters a great deal.

You say "behavior", and I read that as "action". A given action can be right/good in one context and wrong/evil in a different context. I don't know if a non trivial list of actions that are absolutely good or bad can be generated.

First question:

Since I believe that context matters so much, and that requires judgement and discernment, completely intellectual exercises, mental exercises that is, I think the source of morality is our own judgement. Our own heads.