after i killed the serial killer and reported to the Stewart, the quest is complete, but the Strange Amulet is still stuck in my inventory and i didnt get Necromancer's Amulet, these problems are minor, i can use console commands to add/drop them, but the real problem is i cant buy the Windhelm home now, the buying house/cleanup the blood option never appear when i talk to the Stewart, is there any way i can still get the house?

House cant be bought till you do some work for the jarl....

There is a cleanup option? Not for me sadly, that bloody room full of bones is annoying too.

I didn't find that talisman untill I owned the house...

I can't even start this quest. I knew it was a quest because everyone in Windhelm was talking about it, and then I found the Butcher Journal randomly while engaging in sneakery. After talking to every NPC in town with no results, I got frustrated and looked it up on the UESP wiki, and their steps for starting the quest did not work at all. I can't even start it with console commands. This means I can't get the Windhelm house. Kind of a bummer.