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.

there is plenty of combat and exploration, but also have lengthy nice dialog. much of it is influenced by yours skills. the quests are very diverse with multiple conclusions, unlike fo4 that you go somewhere shoot things get items and deliver it.

I've played FNV multiple times, on two desktops and a laptop without experiencing crashes and without using NVAC or the 4GB patcher. I can't help but wonder if the myriad of "stabilizing" mods end up making the game more unstable in the long run. This is anecdotal, of course, but I'd recommend that you play the vanilla game first then apply bugfix/anti-crash mod as (and if) needed.

With that in mind, for QoL mods I recommend the mod that adds fast-travel points in different shops around Freeside, because you have to get past loading screens to go from one area of Freeside to the other, and that's annoying. When you reach Freeside, do a couple of missions in there and you'll understand what I'm saying -- after that, search and download that mod.

I also recommend the mod that adds borderlands-style damage indicators because it helps me know exactly how much damage I'm dealing.