I agree, but if you are seen killing a guard by another guard, it should be an instant death penalty (ie: you can't pay it off with a bounty.)
I agree with this.
Also they should start shouting "Alarm, Alarm. Murder, Murder. A guard is down!"
Or something, that way when 6 guards from the area come running your way its not because of telepathy.
Honourable and braver citizens should try and restrain you.
Also when your a master of sneak and you thump a NPC with x6 sneak and they go sprawling to the earth, right next to their buddy who up and until 10 seconds ago they were having a nice little chat with, the living NPC shouldn't just wander off as if nothings happened.