PKs should only count if you do more than 50% of the damage.

Noobs should only complain when they explode.

Is there even a way to see who did more damage?

Yes, at least on NPCs. The game prorates XP and payouts for hive and border skirmishes.

-1 though. This is silly and disincentivizes players assisting NPCs in defending borders, stations, etc.

-1. Just a dumb idea. Sorry.

I get the killing blow on someone and it doesn't count as a pk because "I only did 5% damage"? -1