I've had the sharing options disabled for every run I attempt, but both my steam friends' captured characters and my own retirement items still appear in the new galaxies I generate for each run. Is there a way to disable both of these, without clearing my workshop folder of all my saved items from casual play?

I've been getting the same thing, no clue if there's a way really to completely fix it.

Dunno much about the issue but as long as you don’t use the characters/items you should be good. If there’s no way to fix it, that’s just what’ll have to be done.

The way that some people have been fixing this issue is deleting the workshop folder in your %appdata% heat signature file

Alright, just completed my defector% run just after doing deleting the workshop folder, and i still had some named item appear, are you sure this technique work for everything?

It should be impossible for you to see the items if you delete the folder they're found in, you could also look at the steam folder if that doesn't work.

I've deleted the workshop folder and started new runs; when I exit the game the folder's totally repopulated with the same items and characters I deleted. Probably has something to do with cloud syncing, if I had to guess.