The build doesn't have the raid support that Afflic is often used for, Shadow Embrace/Malediction. Imp HoT would be a solo/PvP talent and since you don't have Fel Concentration anyways it doesn't matter.
Here would be a pure raid build. Imp CoA is a waste, as CoD is better anyways when you aren't on CoE or CoR. Malediction with CoE would be a raid buff for all casters and Shadow Embrace makes everyone take 1% less damage (and acts as a debuff for Soul Siphon).
Here would be a good solo talent setup. I personally use the solo talents and am doing fine on the meters. However, we have another lock who puts CoE on, that's why I'm not picking up Malediction. Imp HS is optional, having multiple different ranks of it allows more HSs.
Leveling Affliction is just as fast as Felguard (in some cases faster, if you like the playstyle better). Drain Hunting (Send VW in, DoT up) till 30, Drain Tank (Fel Concentration 5/5, Affliction, DoT up then drain life. Higher levels you can DoT 3 up then HoT with imp HoT.) through till 70. Even when going Felguard, generally you should wait till 56-58 for him to get Demonic Frenzy.