Zanbon!

To directly answer your questions:

You see SV hunters running around with haste trinkets because pretty much the only trinkets Dragon Soul has to offer for agi users have haste on them. Your choices for trinkets this tier are Starcatcher Compass, aka The Hungerer 2.0 and Wrath of Unchaining, aka Fluid Death on crack. Also, there’s an on-use trinket you can buy for VP, but meh. On-use trinkets suck.

Haste is not a “useless stat” for SV. Haste is a good stat for a hunter, there are just certain points [haste plateaus] where it is less good. There’s no required number of Cobra Shots for a SV rotation. Can’t fit another Cobra in? No problem. Slap some Arcane Shots in there instead!

Now, some tl;dr to elaborate: With MM, the only reason you HAD to have X number of Steadies per Chimera is because you HAD to keep Improved Steady Shot up at all times, so you HAD to have at least 4 Steadies per Chimera to keep the buff up and depending on your haste, you needed N more Steadies to keep your rotation focus positive. The reason so many people say MM is the “hard” spec is because your rotation has to be essentially PERFECT. There’s no room for error with the MM rotation because you have to stack haste to certain points and execute a certain number of shots in a certain order or your DPS suffers. As much as I love MM, it’s completely ridiculous to have your entire rotation revolve around your focus shot.

SV is “easier” than MM because it doesn’t have those ridiculous mechanics. Cobra Shot serves two really basic functions and that’s it… build focus, refresh sting. You can go for large chunks of your rotation [~15 seconds] without using it at all and you’re fine. You only use it only when you have to. 

I’m not sure how much haste I’ve got at the moment, as I’ve accidentally logged out with my fishing pole equipped and I can’t be arsed to log back in and equip my melee weapon, but as my gear sits right now, I’m at 1915 haste unbuffed. Honestly, 2200 haste isn’t “some absurd plateau” in Tier 13. It’s very, very obtainable through gear alone. There’s a hunter in one of the top guilds on my server sitting at over 2500 haste from gear alone.

Keep in mind armory stalking is dangerous because top players, especially ones in advanced progression guilds, might be forged in a way that is optimal for their raid comp for a specific boss fight and won’t necessarily be a DPS increase for you. Looking at the top hunter on my server, he is sitting at 1259 haste and 802 mastery. Since he’s got more mastery than me and less haste, he’s clearly forging for mastery, right? Not necessarily. Looking further at how he’s forging, you notice he’s not forging IN to mastery, he’s just not forging OUT of it as much as he’s forging out of haste.

When my guild was working on heroic ragnaros progression, I tried stacking mastery one week, fully knowing mastery is complete shit for MM, to see if the Wild Quiver procs would help us get through seed phases. It did, but my damage on the rest of the fight was total garbage, so I went back to a crit/haste build.

It looks like a lot of top hunters are aiming for ~1k mastery, but those top hunters are working on fights that I can see stacking mastery being beneficial due to the crazy AOE you do. I personally like to have enough haste to have a ≤1.5 second focus shot in raid. It’s better to tailor your build to your personal play style than some ideal because you will get better results that way.

Do you feel comfortable with your rotation? Find out! One of the reasons I *love* LFR is because I can try out stuff in a “real” raid environment with [usually] full buffs and sort-of real raid mechanics…… which is a lot more beneficial than standing still in front of a target dummy for 5 minutes at a time.