1. New Vegas is more accurately labeled an RPG with shooting mechanics as opposed to Fallout 4 and Starfield, which are shooters with some RPG elements.

There is quite a bit of combat, but you can beat the game without killing a single thing if you want.

2. Some mods I use and recommend:

Necessary

NVAC (New Vegas Anti Crash) - Hard recommendation.

FNV 4GB Patcher - Hard recommendation.

NVSE (New Vegas Script Extender) -- Necessary for most mods.

YUP (Yukichigai Unofficial Patch) - Bugfixes.

Mod Configuration Menu - Lets you configure mods in-game.

New Vegas Stutter Remover - Hard recommendation.

Necessary for More Mods

JIP LN NVSE Plugin

lStewieAl's Tweaks and Engine Fixes -- Absolute ton of QoL improvements and options.

JohnnyGuitar NVSE

kNVSE Animation Plugin

Not Necessary, but I Like Em

More Perks -- Adds more perks and traits to the game. Not necessarily super balanced.

Fallout Character Overhaul -- Makes the game much less ugly.

New Vegas Enhanced Camera -- Allows you to view your torso and legs in first-person.

JVS (Just Vanilla Sprint) -- Allows you to sprint, using your AP as a sort of stamina bar.

Perk Every Level -- Definitely unbalanced when considering what the developers were shooting for, but I'd personally much rather have a perk every level than every two. Even better with More Perks.

There are more. I would recommend checking out New Vegas' most popular mods on NexusMods..

Plenty of other cool stuff, like new weapons, side-quests and companions. The game is genuinely great vanilla, too, though, and I wouldn't recommend anything too crazy for your first run.

Not so vanilla you go without the anti-crash and stutter mods, though. Great game. Runs like hot garbage.