Raiding as a hunter

Ok, so I've raided as every role - tank, healer, melee dps - except ranged dps.

First of all, I have questions concerning the responsibilities surrounding being a ranged dps, and the specific role of a SV hunter. Depending on fights, it seems like there are many situations which are tuned toward hunters and others which make us look like idiots. I've always seen hunters struggle on fights where they need to stack on a melee player (i.e., Maloriak and Magmaw) and fights where they are stuck in melee range (i.e., Nefarian). What I'm looking for is tips to make the most of these sort of situations or to somehow avoid the drop in damage output altogether.

Secondly, I have questions concerning stats. I know mastery is bad, crit is good, and haste is in between. Is there anything else I need to know? How much haste do I need? With Hunting Party my haste is given a considerable boost, but do I need to build on that? (As far as gemming and enchanting is concerned, I know to go for as much agility as possible)

Thirdly, I have questions concerning rotation and dps output. In order to maximize my dps, would switching from SV to MM make much of a difference? And if there are any problems with my current talent tree, hit me with them (referring to my SV tree - I haven't paid much attention to my MM tree). I'm no hunter expert and I won't claim to be.

Thanks in advance to those good honest people who like helping people prepare for raiding. To you trolls, I thank you for lightening the mood. But if you are gonna be an ###%*%@ and call me a noob, save it and gtfo.
elitest jerks help a lot.

use MM for fights without a lot of movement
surv for fights with constant movement

and yes, for a tank and spank fight you will see MM does much higher dps
I kick ass on Maloriak. Standing with melee isn't really a problem anymore, Blizz fixed hit boxes so they don't screw hunters over.