Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

Build is the basic 24 lock 3 hell fire 3 dragon. 47 AC buffed with my current gear.
At the epic feats I'm torn between a few options.

1: Go full out blast damage.
2: Take 3 fast regeneration for 6 health regen
3: Take the 9 damage reduction (putting it on 15 damage reduction)

I'm leaning myself towards blast damage though not very experienced at high levels.

All are valid choices, it really comes down to preference. Although dark premonition already takes care of DR so you might want to cross number 3 out. Also you might want to consider MaA instead of DS for the extra shield AC

That's actually a pretty good idea, frees up 1 feat and get an extra +1 AC. Won't lose any caster level either.

It is not stated that Epic DR does or does not stack, with Warlock DR on the wiki.
But there are plenty of historic discussions on the topic with people saying that the Epic DR feats do not stack with Warlock DR. Mainly, as they are two different types of DR. (Cold Iron, or Alch Silver) for the warlocks. And Epic DR is just a Flat DR against all physical attacks, much the same as Epic Mobs and Bosses do.
And as Whistler states, the Warlocks get a recastable stoneskin invocation with 15DR.
I've found the 3 fast healing feats to be ample enough to survive long term without using heal pots.

Blast dice is preferred as much as possible. If you are an AC tanker, you are an AC blaster. Put em down hard and quick.

The main benefit I see in DS is the extra fort/HP and tumble, though 27lock 3HF gets a bit more damage and 1 less AC.
I've been toying around with the thought of going 24 lock/3 SD/3HW , you'll sacrifice health for HIPS/evasion and you'll still have tumble.
Shame warlock gets so few skill points.

Cheers for the advice, I'll go with blasting. 6 Regen feels low when you got 450+ health .

Do you use Tower Shields with this build? DS gains that proficiency but MaA doesn't -- also, MaA does get Tumble, no?