How do you avoid "hoarding"?
I dont. Hard drives are increasingly cheap/large. I have to really dislike something to delete it. I have a fair amount of content that I don't really plan on watching again, but someone I know might like it so i just leave it typically.
Also, there's non-rolling limit to how much shows in a user profile. All the delete/modify scripts I've seen work through the user profile, cycling each sorting method to access as much as possible. For old accounts, or just ones with enough activity, there's going to be shit not visible there. Have to search with other means if you want to get everything in that case.