Well, I suppose, but I like the idea of having someone I can trust to watch over my residence. I am a thane in each hold, so my housecarls are part of the package. I'm looking for kills of people who are "friendly" toward me in the game's eyes, but meaningless to my character.

And BTW, having completed the Dark Brotherhood questline, only Narfi was considered a friend, so there were no other freebies in there. But: then I remembered Ondolemar, the Thalmor agent in Markarth's Understone Keep. Since I completed a quest for him, he considered me a "friend," but since he is Thalmor, I consider him an enemy.

And for my last friendly kill I took advantage of a weird glitch regarding Derkeethus (Argonian from Darkwater Pass/Crossing) - once you rescue him, he's a friend/potential follower, and since I'm not big on the non-humans, I'll never use him or need him - so candidate, right? Weird glitch: Derkeethus is marked essential, and even using the console to change this is ineffective, but if you kill him (make him go down into recovery mode) as a follower, it counts as a kill, but he just recovers (he may leave your service, but you can recruit him again anyway). Moreover, if you "kill" him while he's still in follower mode, you won't incur a bounty either. It was also possible for me to kill him outside of follower mode, get the bounty, but when he dies/goes into recovery mode, I see the message about "last witness being killed" and I'm in the clear. So, convoluted explanations aside, Derkeethus gave me an easy out for my last kill and my ebony blade is fully restored.

So, to recap:
1-5. Killed my 5 possible orc followers (played too much D&D to not consider orcs as enemies, or at least, undesirables)
6. Faendal - useless elf since I sided with Sven
7. Ahtar - wouldn't give me his quest, and his axe is worth more to my collection than his life is to my conscience
8. Narfi - contract kill through the D. Brotherhood
9. Ondolemar - Thalmor agent from Markarth (BTW, if only his two Thalmor associates spot your kill, they will become hostile, but you will not incur a bounty for killing them, nor will anyone else join in the fight - just make sure no non-Thalmor's spot your initial kill)
10. Derkeethus - although he doesn't actually die