I'm big into FP, but I've studied Haskell only lightly. Of all the posts I've read about Haskell, this is without doubt the most intimidating.
Clearly, the OP is a quite experienced, skilled programmer, and yet he's been at Haskell for years -- taking books on type theory with him to lunch -- but still struggling with the language at some level.
I believe very strongly that programming in one paradigm can really change the way you think about another (learning Lisp changed the way I program in most languages, for the better). But it really sounds as if the payoff with Haskell just isn't that profound relative to the amount of effort required (unless your real interests lie with abstract algebra or PL research or something like that).
I hope this is not coming across as flamebait. I'm not wondering whether one can profit from studying Haskell; one can presumably profit from studying just about anything in computing. But Haskell really sounds like a very long slog for a relatively small slice of cake.
After a few months of starting from nothing (zero programming experience), my main non-programmer student is now coauthoring a book on learning Haskell [1] with me.
Learning Haskell doesn't have to be hard. It helps to follow a guide designed by people that have plenty of experience teaching Haskell [2].
There is an IRC channel at #haskell-beginners on Freenode.
The author of the post refused to avail himself of other peoples' help, particularly via the mailing list. If you seek help you can learn Haskell and apply it to practical problems in less time than you'd think.
[1]: http://haskellbook.com [2]: https://github.com/bitemyapp/learnhaskell