Thanks for playing, and for the feedback! Glad to hear you like Possession so much!
1) Are you on Windows or Linux? If Windows, 10 or 11?
2) You can delete save files on the Load Save screen. If you select the file, a "Delete" button shows up in the right hand section above the screenshot and other information.
3) The default is that game over occurs after 3 deaths, but you can set that to anything you want (including zero if you want pure permadeath) when starting a new game using the "Customize Difficulty" button on the screen where you put in your name. It's called "Emergency Teleports."
Some morgue information from dead characters is saved, but I haven't gotten around to fixing the display of it yet.