I mean, hematite ain't wrong. Obviously, the staff don't really support your suggestions much at all. Lemme quote my previous comment.
Firstly, custom avatars are rewards for global staff members, exceptional coders, and as a prize for winning stuff like major tournaments (and such tournaments usually appear in news). That point can go for the second one as well, since adding Pokemon to your avatar can be considered custom. So yeah, avatar customization is a reward. Reason being every custom avatar has to be approved and uploaded by Zarel himself. Not even other admins can upload without his consent. As for your third one, it already does. It states such as illegal or banned, and you can find an entire banlist by doing /tier (format).
So yeah. Custom avatars are meant to be rewards for a reason I quoted. They aren't supposed to be available for everyone. And it already shows guidelines and stuff as to what is banned by showing what is banned as banned or illegal.
But on a separate note though... You cannot yourself upload all of those. I think you'd need to be an admin to do such. Such is why this forum suggestions exists. So that staff can look it over and see if it is worthy of uploading. And, it seems like staff and normal users don't seem to want your suggestions all that much. So even if you was to reach 20+ likes (which is hard on it's own, I have MANY comments and only 2 got that much), you just simply won't have the ability to upload them yourself. You'd have to be an admin, but like I said, they don't seem to be all that supportive of your idea, as shown by Hoeenhero. I myself think that custom avatars should stay as rewards. As for reasoning, I have many, but 1 big one is it shows just how much a user might've done for PS that should be acknowledged. If anyone could have one, then they simply wouldn't be nearly as cool and they'd have to make more ways to acknowledge what a user has done for PS.