I never had the cold start issues. I used to use (and still do), the stock fuel injectors. It has always seemed sufficient enough for 5psi of boost.
I did have problem with the engine stalling when the BOV blew to the atmosphere. I now know how to resolve that with an SAFC Decel function. Back then though, I had recirculated the BOV back into the intake. The problem then was that when the BOV purged, the part where it tied into the intake was at a 90 degree angle (Perpendicular). So as the air went back into the intake, some went towards the turbo and some went towards the Maf sensor (backwards). It disrupted the reading and caused the car to stall. The BOV tie-in was cut and re-welded back in play so that it was angled at 45 degrees, towards the turbo. This prevented the air from the BOV purge from heading back towards the maf. No more stalling! Happy driving ever sense.
Currently, the OBS is not tied back into the intake and I am using the decel function of the SAFC Neo. It works fine but I have not been driving the car for over a year. Too lazy to fix a check engine 'speed sensor' indicator that comes on over 40mph.
Glad to read that some/most of your issues have been resolved. And if someone tells you that turboing your car can not be successful, I am still the only owner of my OBS since late 1996 (new). It has been turbocharged since 1998 (or was it 1999?). Have fun!