Just one issue : I see a bunch of 2WF feats, but no second weapon. The dorn-dergar is not a double weapon so I'm confused.
Maybe he meant to say the 'urgrosh'- the spear ax thing. It seems easy to confuse the two since it is 'dwarven' and such.
Ah, now I understand it- Dorn-Dergar Master is a feat that lets you use this two handed weapon as a one handed weapon. Which could be used in TWF using the fighter archetype.
Dart viper also lets him switch between reach and non-reach with a swift action instead of something longer. Not the most effective feat on a TWF build (since each one would need a swift action)... but eh- you could make it a tricky reach style if you go large, so not useless. Effectively filling in the doughnut of large reach users is worth something. You have options... although you could consider delaying that option until later.
So to clarify- this is a TWF build that uses reach weapons. Lets think of that as we continue into this discussion.
Well then, onto actual advice- lunge. Lunge is a very important feat for reach builds. It only lets you get an extra 5' of reach during your turn... but that is plenty.
With it, you can full attack enemies from 20' away. That is great for a style and archetype that focuses heavily on the full attack. Who doesn't love more full attacks?
It can also be used for positioning. Normally, when you attack first with reach weapons, the enemy ends up close enough that they can just 5' step past your reach. Thus, the enemy gets their full attack and you don't get your AoO. But with lunge, you can attack from far enough away that the enemy still has to take a proper move action to get to you. You get your AoO, and they probably lose their full attack.