2) I think you're overlooking that you need a free hand to reload your guns, which is the main obstacles to Guns Akimbo type builds. That would somewhat preclude getting 6 shots a round at level 3,....
Me thinks he plans to have 1, Double-Barreled Gun, and just give them both barrels every 'shot'.
So there should be no reloading problems, and no Two-Weapon penalties.
[currently semi-retired from the forums, will occasionally check private messages]