That version of Amp. Curse doesn't yet exist, but it will. I also assume that you'll be using Curse of Doom rather than Curse of Agony in a raid (unless Pandemic affects CoA, which would give it a better DPS and DPCT than CoD by far). Corruption, after Everlasting Affliction, won't be recast by an Affliction lock, and also therefore does not scale with haste. Immolate and UA cast times are all that are affected by haste. Oooo, a whole 0.5s off SL. Whoopdedoo. Wrath of Air along with haste implemented on gear will already probably lower the GCD to 1s anyway, so your point is not particularly valid.
So the DPCT goes up, but that doesn't change that the DPS goes up if DoTs ticked faster than they do now. Currently, your Curse of Agony does 139.708333~ DPS (3353/24). With any amount of haste, your Curse of Agony still does 139.7083~ DPS. If haste affected DoTs, say your CoA duration goes down to 21 seconds. Your DPS from CoA would go UP to 159.6~. That's an increase of almost 20 DPS, in addition to being flat 3353 DPCT from a 1s GCD on curses. Realistically, though, you would be casting CoD over CoA. And speccing 21/40 in Sunwell. But that's aside from the point. The fact of the matter is, DoT duration scaling with haste is ultimately a DPS increase, and in order for Affliction warlocks, Demonology warlocks, Shadow priests, Moonkin druids (Insect Swarm, Moonfire) and Fire mages (Ignite, Fireball, Pyroblast) to benefit to the best possible ability, DoT durations need to scale with haste. Now, tell my why you wouldn't actually take an increase in DPS. Tell me exactly why DoT duration shouldn't scale with haste. And give me reasons to back it up, because right now, I think you're full of ****.
As far as hit, the math has been done that we'll need 236 +hit to reach hit cap (since they are removing the 1% unmitigatable hit), or 9% hit. Suppression and Cataclysm are a crutch, and anyone who can't reach hit cap before raiding is lazy. Blizzard made it possible with Heroics gear in TBC, and there's no foreseeable reason why it shouldn't be possible in Wrath. Still, Soulshatter isn't a "good" reason to stack hit, it is THE reason to stack hit. It's the same reason that Survival Hunters usually take a point in Improved Feign Death, because of its resist mechanics.
In terms of mana regen, they nerfed Fel Armor and made it 2% hp5 instead of spirit based mp5.