Not picking soul siphon as affliction lock is like going destro without Devastation. You miss insane ammounts of damage done by not having it.
Soul Drain, boss maxdotted and under 25% hp, ring a bell?
3 points in eradication is bad as well. 1p and by then you should have your haste from gear already covering more or less for the additional 2 points
also (eradication doesnt stack with hastegear).
It's only debuffs on bosses that are calculated per tic. All trinkets and your talents only give the extra damage if you use them/they proc before you cast your spell.Thus taking 1/3 molten core and glyph of immolate, makes immolate a bit more useful and worths casting.
For example if you got a trinket like Hex Shrunkenhead you must use it before you apply your dots in order for them to get the extra damage. If you cast lets say corruption then use the trinket it won't benefit from it.
Same goes with talents, in this case Molten Core. If you got immolation up and molten core procs it wont get the extra 10% damage and I sincerely doubt any warlock want to recast a immolation with tics left just to get the 10% damage.
Sorry to say Nataya but my advice is that you pick a better spec, you really miss alot of damage due to bad talentpoints. Cheers mate