The only essentials that I would pretty much blanket recommend are:
Legacy Reborn Texture Pack
Atmospheres - Weather and Lighting
And pretty much anything Balebandr0 has released as part of his "physically based" collection
https://next.nexusmods.com/profile/Balebandr0/mods
You can get New Vegas Reloaded (requires joining their discord but it's easy to find) if you feel like dealing with it and only using a couple of the shaders like volumetric fog and tonemapping in the settings menu. Most of the others will look iffy depending on location and sucker **** your framerate.
Classic Fallout Weapons Remastered & Hit - Classic Fallout Weapon Animations - Part 1
Tammer's NIF-Bashed Armor Mega-Pack
https://fallout.firedrakecreative.com/doku.php?id=armor
Anything else is going to again depend on personal preference.
No clue what you mean by this.
Don't think anyone has but frankly being an annoying **** voiced by felicia day is the bigger issue imo

I'm just stating the facts.
Question is are you going to gargle the truth or swallow?