Are you planning sanctioned races to compete in , or is this just a sports bike?
1, bb7 road is short pull made to be used with brifters, high MA in the lever..
[note TRP is about to release 2 new cable operated disc calipers]
SRAM is about to release an integrated in the brifter hydraulic brake.
&2) look around the Pro Race coverage of Last years UCI Race season, Di2 has already
made inroads there , in the sponsored racers gear.