re: Affliction. There is no 'rotation'. Keep haunt up (overwriting it is fine, it just has to stay up). Maximize dot uptime (if you can manage 85-90% uptime on Corruption, SL, UA, CoA when you analyze your WWS parse, you're doing good). Never interrupt a cast for any reason.
I have managed over 5k DPS on patchwerk in 25man, and 4.5k in 10man both using Felhound. You can get higher using Doomguard or a well-placed infernal.
http://www.wowhead.com/?talent=IfxrbzMAoqq0IstZqzhV is the build to use if you only have 10% hit on your gear (11% on if you're a horde). In a 25 man raid you should be able to count on 1% hit Draenei racial +3% hit from Boomkin / Spriest, and you should definitely spec and gear appropriately. The more points you can take out of the hit talents to put into DPS talents the better. If you don't have any problem with threat you can take points out of improved drain soul, but currently affliction threat is through the roof (you get extra threat from the healing on Siphon Life and on Haunt).
Bosses you should trounce the rest of the DPS on and you'll pull aggro if you're not very careful with soulshatter, are Heigen and Malygos. The boss you will do absolutely horrible on is Gothik. Your trash DPS will mostly be sorry relative to a destro lock.
Gear
Spellpower. That is the stat you are after on gear, plain and simple. Haste is a little better than Crit, but you shouldn't go out of your way for either. I personally like to try to keep them about even (500 haste / 500 crit is a decent goal to shoot for, with 2400 spellpower self-buffed with felarmor). Often there is nearly equivalent gear for a slot where one will have SP, Crit, Haste but no spirit, and another will have SP, Crit or Haste, and Spirit - the item with spirit is better.
Tips
Cast UA then Immolate always as a unit - treat them as a single DOT. This will make keeping all your dots up easier as it effectively makes them into a single dot as far as keeping track goes.
Stop casting immolate when the boss is at 35%.
Drain Soul below 25%, but keep all of your dots up. Interrupt drain soul to reapply dots, but be sure to break it immediately after a tick of damage.
Glyphs should be Corruption, Siphon Life, and Immolate. That combination is the highest DPS you can get from glyphs for affliction at the moment.
Use either Potion of Wild Magic or Potion of Speed in the execute range below 25%, this will yield the highest DPS increase.
Do NOT use Life Tap for the bonus damage from 4 piece T7 - use it to get extra mana back so you have to tap less. What I usually do is tap when I get to about 40% mana, then tap again before the buff wears off, then tap again before the buff wears off all while casting in between. You may have to repeat that sequence twice. If you end the fight with zero mana the instant the boss dies, you win the mini-game.
Teleport on opposite side of the gate for Gothik lets you get more DPS time on the boss. Teleport in the middle of the platform on Malygos lets you get out of the Vortex and continue to DPS (careful of threat).
Infernal right after a decimate on Gluth positively owns the adds.
Go practice on a Dummy. Ignore the DPS numbers that you generate. Lifetap or whatever you need to do so that you can DPS the dummy for 5 minutes uninterrupted. Look at your recount and calculate your DOT uptime for all of your dots including immolate. Write it down and repeat the exercise until you can consistently keep an uptime of 85%+ for all your dots.