Self proclaimed master of Fallout New Vegas? I'll have you know I would challenge you for that title, your hàrdcore (why is that blocked tho?) settings mean nothing to me, I play with the most realistic settings I can possibly manage, a single shot from almost anything means near instant death and I don't wear power armour because it's ugly.
In all seriousness though, pretty much everything AJ said is entirely accurate as hell, although one slight suggestion would be if you really want to survive then build towards a 'sniper' build and always carry a scoped rifle, a shotgun and some kind of automatic weapon with really high dps for those "oh shìt" moments. Also yes on Spice of Life, as someone who goes purely for aesthetics with my characters and couldn't care less about DT, despite my stupidly hard settings, the backpacks are brilliant, because where the **** else are you carrying a thousand stimpacks, and some of the clothing is definately useful, although the majority of it is designed for aesthetics over practicality.