I truly don't think the answer would be to Animal Crossing Items remove them entirely. People today come from a very vulnerable area posting those and are trying to offer their heart to a safe community they expect will accept it. I believe that it could be really detrimental to find an automated delete in return.
Also regarding spoilers and time traveling, I know think it's a remarkably difficult thing to medium concerning seasonal events and things. I do however think that spoilers might be used for some time locked items (like the mario items) that are hacked in prior to their release date. This would be taxing to moderate as there is a fixed release date for the items and the spoiler tag could be enforced from the afternoon of the update to the afternoon of item release. It is not something that disturbs me personally but might be something to think about.
On shared occurances I think that milestone posts are great for the subreddit entire as creature crossing is mainly a game about setting your goals and I think that it's good that people have somewhere to discuss them. I am also very sympathetic about the sticky limit and with that in mind I think that the present codes and queries threads do a decent job of keeping the subreddit clean.
Anyhow that was my 2 cents, I think you guys are doing a great job with buy Animal Crossing Bells the subreddit and you're taking it in a good direction!