Only spec STR when you completely out gear the content you're doing. Otherwise, if you want to do more DPS, get HQ DPS accessories. Going full STR when you're undergeared is just being risky and putting stress on your healers. Don't do that.

There's basically no point in going 30 VIT in 2.1 once you have full i90, that extra HP cushion isn't really doing you a lot of good at that point. Once 2.2 hits I'd respec for 30 VIT again, though.