from a purely theoretical viewpoint, lol, i very much doubt u have any issues with your pump, regulator or injectors

i doubt changing the wiring to the fuel pump will change anything at all

like DLO01 said, if you are still convinced that it could be a problem with fuel pressure, check definetley

i think its an ecu/tuning issue more than anything....but you have power fc, so maybe tuning problem..

if u get a new MAP sensor make sure its good quality, lol........i have nfi what the limit for a stock MAP sensor is