IllinoisBoi1 said:
I just want to know why you can’t delete notes from their history and why the sets don’t work. I’ve tried picking “owned” or “maintained” and nothing works, I’ve tried clicking the add button, too.

well, if you mean why you can see the history of notes.. .well.. I present to you a concept:

• Kinky McFoxy uploads some Horribly Lewd Japanese Comic.

Yamanda Taroneko-san helpfully translates all of that sexy lewdness.
Bob Furryson rages unresonably because... well, shit, I don't know why people flip out and thing that deleting all the tags off a post, or spamming is a good idea, but it happens sometimes and today, Bob Furryson is the dude who's raging because he just cannot deal with that Horrible Lewdness.
So he deletes the notes. Because if he deletes the notes, he makes it harder for people to enjoy this thing that enraged him. If he deletes the tags, he makes it harder for people to find the thing that enraged him.

So, we keep the history around, so that any person can be a good neighbor, so to speak, and fix what was broken.

Or another scenario:

• Kinky McFoxy's at it again, uploading lewd things.

Kandi Neko-chan is sugoi at her nihongo because she's been taking it for the last roku months, so she can totally translate this manga doujinshi that makes her little kokoro go doki doki. She "translates" as best she can, leaving out words here and there, guessing at other places, and generally not doing very good. because Japanese is pretty hard.
Yamada-san comes along, deletes her old translation, and replaces it with his own translation.
Kandi-chan OBJECTS! her translation was SO kakoi! How could he be so hidoi! to a kawaiisou bishoujo like her! She deletes his notes and replaces it with her own. Ganbate, chibi senshi
Kink McFoxy says "um." and puts Yamada-san's translation back.
Kandi objects again. and replaces her own.
Someone, somewhere, lets the staff know that there's an issue, and they can easily have a look and see who's translation is better, and who's being a little brat.

as for sets--I havn't had a problem with them--what exactly are you having a problem with? creating one? Adding to one? be more descriptive :)