Few QuestionsFollow

Firstly, hello all Allakhazam forum users! I've been viewing the hunter forums as a guest now for some time, and would like to thank everyone who posts the answers to questions and whatnot, as it has helped me no end in gearing up my hunter ( special thanks to Aethien for his pre-raid gear guide, really got me into heroics nice and early ).
On to the questions :)

My current stats are:

1942 Attack Power
27.31% Crit
142 Hit Rating
9000 Health, 6600 Mana, 613 Agility unbuffed.
DPS Output is anywhere between 1000 - 1200, but I have only done Gruul, Magtheridon, and Zul'Aman (my server is not very good raid-wise).

My spec is the BM/MM cookie cutter build.

On many topics, I've seen a lot of people advising that, at 30% crit, ones pet should be switched to a windserpent to maximise dps. My question is, how exactly does this boost your dps? And should I be looking to tame a caster serpent, or a melee one? Note: My current pet is a Cat (Quetzalcoatl by name), who is trained in Claw, Bite, and Growl.
If anyone else would like to give me other general advice on improving it would be much appreciated :) My armory link is http://eu.wowarmory.com/character-sheet.xml?r=Darkmoon+Faire&n=Ploible
Thanks
-Ploi

Your stats look nice. Nice to also see someone who actually used the sticky instead of making an account to ask questions that they already had the answers to.

I would suggest getting Dive when you get your Windserpent. I like it because it makes killing things faster because your pet reaches its target faster.

I got the Windserpent out of Netherstorm. That might be the one that most people have but it's the closest to level 70 and it's right kind you need to get.

Thanks for all the replies. Generally, my pet does have over 50 focus almost all the time, so I should just get the windserpent from Netherstorm to maximise DPS?

The thing I most wanted to know, is WHY should I get a wind serpent? How exactly do they increase my dps?

As any spec technically, as long as you have the "Go For The Throat" (under Marksman) talent with 2 points invested. The whole reasoning behind switching to a Windserpent is that your crit should be high enough to sustain constant Focus Regen for your pet. With every ranged crit you preform your pet receives 50 Focus, which it can then use instantly to cast out Lightning Breath.

Now the key to remember here is to not have it on Auto-Cast. There's a small bug with a Wind Serpent where if Lightning Breath is left on Auto-Cast they will constantly move out of melee range in order to cast Lightning Breath, then they will move back into melee range to deal normal damage. If you add it into your macro instead, it will cast it regardless of range, and won't bug out on you.

As said before though, a Ravager won't be able to use the Focus fast enough with the same global cooldown. So you're just wasting extra focus by not having a Wind Serpent, which just hinders your DPS. Not by a whole lot, but overtime it can become quite significant.