If you run the numbers on GWF, polearm mastery warlock vs. EB, it *is* more damage in most cases to be in melee. There are a few levels where EB will do more damage, specifically levels 5, 11-12 and 17+. That does not count the extra reaction attacks you get for polearm mastery.
Dex based fighter 2 in my group just took his first level in warlock, with hellish rebuke and hex as spells. Curious to see how it plays.
You don't need GWF, sword+board is interesting as well, but GWF is definitely the highest DPR option. The big difference is the polearm mastery feat giving the bonus attack, so you can apply hex damage again.Do you really need GWF? That's like a 1/2 point extra in damage right at the cost of 2 or 3 in AC?
How's the monk do?
Four attacks at 2d6+4 at 5th level with no feat investment.
I guess that is the other way around though Monk X/Warlock 1
(2d6 + 4) * 4 = 44 DPR so it is definitely higher at level 6, but really you are mostly a Monk at that point and don't get access to 9th level spells.
You probably want Warlock 2 so that you can get invocations and hence EB for ranged damage. Monk is quite MAD already though, so adding Cha is tough.
I am really a fighter with a few weird tricks rather than some sort of wizard.
I feel the exact same way. Although I have found that as I increase in level it becomes harder to resist casting other spells instead of hex.
Last night was the first time I didn't cast hex in a game (Fly-REST- Fireball, Misty Step)

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.