Oh god, are you 12? Maybe even less. yes, Thomas is nothing that wasn't in Skyrim to begin with, just a skin and some effects (applied to what was a dragon).
Damn, you don't comprehend the basics? Yes, "firearms", i.e. PROJECTILES have always been in Skyrim.
Many modders are software developers in their day job and write their own code, e.g. in Python for Skyrim. Have you ever seen the variety and standard of the BDSM mods on Lover's Lab for instance?
Lover's Lab is owned by a lady called Ashal who wrote a mod called SexLab Framework. This mod being a framework provides the mechanism for other modders to utilise for the purpose of sex animations. Nothing like this exists in the vanilla game.
Can you comprehend a difference between adding an animation, skin or effect and adding completely new mechanics? Well, of course you can't, obviously.
There are animation mods created in animation software and imported into Skyrim; a skeleton (not the undead creature) built from the ground up to allow better animations. Dozens of new creatures with skeletons, meshes and textures all introduced into Skyrim.
Still no examples of anything that wouldn't be normal for Creation Engine. New skeleton? So what, it's just a different variation of the one already in the game. Adding a new skeleton is no different from adding another mesh or texture.
BG3 has no excuse for having a below average CC.
The only true thing here.