I've killed one of my own NPC's in the game, who later got raised, but I don't single anyone out.
*chuckle* As far as there being "far, far more entertaining things you can do to his character than kill him." I've done far more interesting things, one of the current characters started the game by waking up in the gatetown of Hopeless with his clothes, a sword, cut purse strings, a smooth black gem embedded in his ankle, and no memories whatsoever. In fact that character for the first plot of the game would periodically lose time as he was posessed by an outside force exerting its control over him through the gem in his ankle. Ended up using that as a subtle tool to manipulate what the entire group did, letting them think they were doing things of their own motivation, or against the forces they suspected of having taken the one characters memory.
Wasn't until the end of the current plot that the character ended up regaining full control of himself, and most of his memories, and a full understanding of just what had happened to him leading up to his waking up in the gatetown to the Grey Waste. The player of the character was having both an amazing amount of fun with her character, but was joyously frustrated at times trying to figure out just what was playing with her PC.
Fun plot element it was. The same character may have inadvertantly overexposed themselves to heavy magic, with some nasty side effects, depending on your perspective. I don't give out power items without their being potentially horrific side effects for having them. I'd say a few things about an item floating around the group, but a few of them may read these boards, so I'm loathe to mention it specifically.
But yeah, there's many other fun things to do besides kill a PC for doing something stupid, unfortunately the prior two times in question for my original problem player, that was the only real option on my part. We'll see how it goes in the future though once I have a talk with the player.
And with the NC game day, I'll have to see if I can't attend.