>died in a room with door locked and windows sealed
>they specifically mention no rigor mortis, so the death was shortly before his body was discovered
>they specifically mention the dead guy made a lot of noise and commotion, stomping around and shouting before he died but nobody actually specifically saw him - possibly already dead and the killer trying to hide the time of death?
>supposedly overdosed on sleeping pills, but the doctor mentions it's next to impossible to force-feed someone a large enough amount of pills to kill them, so the sleeping pills are presumably to hide the real cause of death?
>the record player is pretty clearly a distraction, somebody set it up to keep them away from the murder scene to buy time
So my current theory is that somebody killed him (maybe he found somebody rooting through MC's stuff and the killer wanted to cover it up?), made sure people saw him, made a bunch of noise pretending to be Funeno and at some point they'll say "I can't be the killer, we heard him making noise AFTER I was with you guys, I didn't have a chance to slip away", set up the record player as a distraction, used the record player distraction to do something to hide the evidence, maybe set up the sleeping pills? I still don't have even a guess for a lot of stuff, like how the locked room was set up, but I'm also missing a lot of evidence so far.