The master cyl has two outputs connecting to the ABS unit. Are both outputs in series and paths linked inside of the ABS module? If this is the case, then you are right the master has nothing to do with the issue; otherwise I do notice the master has two outputs on it.
I just bled all the pipe fittings from ABS module back to the master cyl (8 fittings total) and no difference in braking distribution. I almost want to unbolt the ABS module and level it out or even shake it a bit; bleed one more time. I'll check into this.
Another thing I notice is the F-to-R conenctor which appears to be on top of the passenger wheel well. The service manual:
http://www.nicoclub.com/FSM/370Z/Coupe/2010/BR.pdf , page BR-22 is showing a physical connection labeled A or 2. I'll have to check this piece out to see if any air might possibly be trapped inside.