This game looks good just for the ability to recreate famous killings from history and fiction. I'd like to:
-Kidnap an NPC, tie him to a chair, cut his face off, show it to him, then nail it back onto his head. (Preacher)
-Seduce a prostitute with grapes and laudanum, murder her, cut out several of her organs, and send one to the police. (Jack the Ripper)
-Make a vest with tits on it. (Silence of the Lambs)
-Send taunting letters to the police and news outlets, possibly influencing NPC behavior, like making some of them wear specific clothes or carry specific items. (Several, but specifically the Zodiac Killer wanted people to wear buttons with his symbol on them.)
I think if I was going to be original about it, I'd be the Thighbone Killer. Start by raiding a mortuary or graveyard for a leg or thighbone. Process the leg into a thighbone if necessary, bludgeon someone to death with it, leave the murder weapon there, take the victim's leg. Repeat from step 2.
With that on the table, I do wonder how robust any crafting system would be. A Rube Goldberg device may be out of the question, but breaking off a chair leg or something should be possible.
Also if multi-story buildings are put in, it would be fun to fling severed body parts or whole corpses off of them. Maybe it could actually help with corpse disposal. Track your victim and keep track of when garbage pickup is. Go to his high-rise, push the dumpster under his window and murder him before the garbagemen come. Throw his body out the window, into the dumpster.
GARBAGE DAY! (I know, I know, not the same at ALL...)