You lost me at the Gates Drive. That thing is not really practical, and runs counter to other decisions like 26" wheels for wide parts availability. But your other decisions make a lot of sense and it looks like you have a really nice bike there.
Personally I would like to run two front brakes anyway. I have have brakes fail moderately on several tours. And I run the very best stuff, so I think it makes sense to have two front brakes for safety. More likely to save you than a helmet.