@Farlander in fact the idea of an additional sparring flag could be nice, in the future, or maybe an arena where you cannot die and don't lose karma when hitting other players, no matter the alignment.
But probably right now the devs have other things to do to keep on par with deadlines, so it might stay as an idea for the future, for a more stable and complete version.
Right now you can go with the slight karma penalty, if you don't go for the killing it shouldn't hit you much anyway, nothing you can't recover with a little PvE against evil creatures, I suppose.