Hai Crantz
and welcome to the darkside!armory is bugged for me
so i cant really see what kind of gear you have. Tho i may give you some pointers 
Gems :
+spelldmg are the best gems to get for you warlock, If you can get a +dmg socketbonus with a Yellow socket... then you can use a +SpellHaste & + Spelldmg Gem.
You will also need 2 Blue gems for the Crit meta gem. Try and put it in pieces that will give you a good socket bonus.
immolate:
Its correct that its useless to cast immolate if you dont have CoE and 5/5 Imp Scorch up. Conflag should never be used in a raid. it decreases your dps.
Tho the increase of casting immolate versus not casting immolate is around 20 to 50 dps. Add the extra mana cost to it and the decrease of ISB uptime its better to just not cast it at all.
Specc:
Currently im specced : http://www.wowhead.com/?talent=IZdxczIbzZEx0tr0zuhi
Full shadowbolt nuke build. ISB to increase shadowdmg even more.
Rotation will look like :
Curse > Shadowbolt > Shadowbolt > Shadowbolt > Shadowbolt etc... and lifetap whenever you have to.
If you look at Aneri's armory page.. You can see that she does it abit different... Shes is a fire specced warlock.
Immolate > Incenerate. Etc. Tho this spec would work aswell. I would still suggest you take the shadowbuild.
ISB is a really good dps boost to not only you but also shadowpriests.
Oh! And you will most likely pull aggro every trash pull. So be nice to your tanks! and tell them to Intervene you from time to time :p
EDIT :
My specc has Nether Protection. That means you can go immune to fire and shadow spells for 3 seconds....
If your the tank for Leotharas in SSC or Capernium at Kael or Illidan... You should put thos 3 points in imp Searing pain.
Since if you become immune to a fire/shadow spell when tanking, the mob will select a different target and starts casting on him ;D
