I think if you choose to pay/go quietly for committing a crime there should be mandatory jail time on top of the fine. After all you did just kill someone, and I think it would make going to jail happen a-little more often. If you can't pay you get more jail time. Could make for an easy yet cool mod.

also should be depend on region. some place has strict law enforcement while some other place has corrupt government

The crime thing is not there for reality... It is there to remind honest people that they did something wrong.

Like reality, jail and prison is just to please the others around you. It is not there to do anything functional for you. The illusion is that society is better/safer with some form of petty enforcement. (It is truly there, so people can justify paying $100 in security taxes, seeing that $1 was spent in security. Punishment only works on honest people... Thus, the reason it fails... on dishonest people. Like DRM, it only hurts the ones who support it.)

After reading this, I have some crazy idea to imagine a Skyrimized ''Chronicles of Riddike: Escape from Butcher Bay'' [Game] type mod.

My gosh that would be sick!

On the other hand, you are the #1 candidate for savior of the world, it's possible the guy you killed deserved it, and OMG THIS GUY JUST KILLED THIS OTHER GUY LIKE IT WAS NOTHING SO I'LL JUST ACCEPT THIS PAYMENT AND WISH HIM A GOOD DAY BEFORE HE DECIDES TO KILL ME TOO!