@ Gizmo if a player attacks you or steals from you they go " unprotected " and killing them would not affect your karma. thus defending yourself is okay and does not affect karma.
So if someone is blue, but he hates me and often kill me, but i am weak to "charge" my blue karma points, i cannot attack him, until he will attack me first?
I dont want to continue with this debate, i want only show you, that even simply karma system has many many bugs and you are offering anything new, there were better, but still very limited ideas that could be exploited (i.e. "charge your blue karma via killing bad alts,..).
No, best solution is no karma at the moment. You have safe places, you have danger places, arm yourself, make group with another players, this is the solution.