Damage Threshold can just fuck right off. I cannot kill all the Deathclaws in Quarry Junction without either setting up a minefield (and so far all my mines hasn't been enough) or exploiting AI by perching in an unreachable spot. It's ridiculous. Definitely needs some Nerfing.
If you got high HP and some heavy armor just get a good unarmed weapons. They seem to bypass Damage Threshold. That or get some Armor-piercing rounds.
Or I think I read that you can try to cripple their leg(s), rendering them really slow and unable to pounce. So then you can just pump them full of lead and be done with it. I also read that in Fallout 3 you could use a needle gun to instantly cripple their legs, but I'm not sure if there's a needle gun in new Vegas? If so, it should work as well. But good luck crippling them without it. They seem to have a bunch of damage threshold.
Also the accuracy issue- some reason, I have horrible accuracy in VATS in this game, even with the commando perk and necessary weapon. And even when crouching. Unless I'm right up in their face, my accuracy is usually way below 50%. I have around 55 points into guns as well, though I'm not sure if that matters.
The strange thing is, I've noticed that the accuracy tooltips don't really seem.. accurate? When I'm using a 10mm pistol, and for example if I VATS somebody in the face but the tooltip says 40%, I'll hit their head as if it was actually 70%. I'm not really sure what to make of that. This doesn't happen with my assault carbine. I have a much better time just spraying the enemy down with it, VATS is useless to me there. But again on the flip side, my sniper rifle seems to work in VATS. Maybe it's the bullet spread that's causing this?
Oh and I have a related question. For some reason it feels like damage threshold is treated differently in VATS than it is when you're just firing shots without it. Actually, it's the estimated damage done bar that's throwing me for a loop, it rarely shows what will actually happen. And I am taking criticals into account.
Calhoun, I was wondering about that too, but so far I think the only way to side with them is to do their quests and gain favor. Eventually
they'll be giving you an emergency radio, and extremely important NCR quests.. as if you were one of their own. Though they often mention that you're not a part of their group. It's kind of lame, you'd think that being recruited would make more sense, but "the savior of the NCR" isn't good enough for that? I know for a fact that you can fight for them on the Hoover dam without having to take control of New Vegas. You do have to get rid of House, but you don't have to do anything beyond that.