All add-ons (Skins, plugins etc) are from the mods here, nothing from the users
I don't think that's quite correct, and to avoid misconceptions about this;
There is only one developer/coder for MusicBee (Steven)
There are many, many users that create skins, translations, icons, plug-ins, etc.
Mods are just regular members who at one time volunteered to help in keeping the forum 'clean', mainly removing spam etc. That title and it's 'privileges' have nothing to do with having coding capabilities, having more knowledge, or contribute more to MusicBee than any other members.
I think I was mainly referring to the fact that I feel that most add-ons are in the categories of visuals and functional extensions. Almost none in the audio category.