It's hard to tell when a creature has been killed and by who, you don't have to kill an opponent to defeat it, and it's hard to say when an opponent has been defeated (it depends on your goals). You don't get XP for killing things; you get skills by using them, including combat skills. A creature could be mangled unconscious on the ground, and the player wouldn't know whether it's dead or alive without inspection, but that doesn't change the fact that the player was fully victorious. I don't want to encourage people to hack up every half-living body they find to get points (although some might do it anyway!)
On the other hand, tracking player kills/defeats is fairly important.
Also, that scoring system would be temporary. Ideally, when the game comes along, the player should be able to get a high score with ever committing an overtly violent act.
Hmmm.... one possible method would be to add up all of the skill gains that your player has made. This would make sense from the sense of character building and is somewhat sensible in combat turns (since you gain many skills while fighting). The problem is that it doesn't account for risk (a character that bakes bread the entire game would have a high score -- this isn't necessarily bad). If we want to account for risk, then we can just say that skill points gained in adverse situations are worth 2/5/10 times as much, or whatever the risk factor is.
In the end, by its very nature, assigning a score is making a value judgement on certain types of game behaviors. A lot of people prefer hack-n-slash, so a score based on kills/combat would make sense there. However, that would shut out people playing for other reasons (once the game is more complicated -- right now, there are no other reasons )
In the end, I might have something like "Armok's Hall of Blood" (for warriors), "Armok's Hall of Infamy" (for criminals/evildoers, etc. Because the types of gameplay can be so diverse, there is no sense in comparing them -- 4 or 5 such Halls would probably be sufficient. Maybe that works.
For now, I'll just keep the Hall of Blood that is already in (scoring is now based on the number of hits you score -- I'll change that a bit... probably defeats + skill gains).