Someone posted this on NeoGAF:
Maybe Boone did all the hard combat work ?
Anyway, extremes and technicalities aside, the game offers a good support for roleplaying a more pacifist character and that´s where speech and some other non-combat skills become especially important.
Just another thought on leveling mods. I downloaded a 1.5 mod and have been running it for most of this game. I just hit level 19 last night and I still haven't dealt with the guy who shot me in the head. I've not even met my benefactor from the Vegas area. I've done a TON of stuff in the game but I bet I'm still missing up to a 1/3 of map. If someone is a completist, I could see going to a 2.0 slowdown mod right at the beginning so you don't level too quickly.
Keep in mind that with 1.5x, at level 20 you´ll have around 45000 experience points gained, but to reach level 30, you´ll need another 55000 to gain.
Imo, there simply isn´t much more experience to gain in the game unless you grind respawns quite a lot.
Grinding aside, 2x slowdown is imo more suited for players who plan to play the game thoroughly, but actually don´t want to reach max level, at least not without sacrificing 3 perk choices on Swift Learner, and use the slowdown more as a means to make the game more challenging when it comes to skill gain/ skill checks (to a lesser extent this applies to 1.5x as well of course).
Everything over 2x is definitely overkill.
The "good" ending:
Talk to the robot Yes Man (locked away in Benny's room at the Tops) and become the ruler of Las Vegas yourself by doing his quests.
Bumping the difficulty is definitely the way to go, the game is still nowhere as hard as the original Fallouts were but it's quite challenging even against humans.