These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Misaimed Fandom: The tags on AO 3 were initially intended for readers to filter works, characters, pairings, and triggers, but writers have developed an irritating habit of inventing irrelevant "fun" and "cute" tags and including them on the tags list for who knows why, much to the consternation of readers and mods, who are tasked with sorting said tags.
Actually, it's more to the consternation of some readers. The AO 3 admins and tag wranglers have repeatedly said the "fun" and "cute" tags don't mess with the system any more than regular tags, and in fact, the useful canonical tags are much more resource-intensive.
There Are No Rules: Well, not really, but the content policy is /extremely/ lenient; there are no limits to how extreme the content within works can be, and works are always tagged and rated according to the whims of the author.