The stock regulator should be fine for getting you running (it fine how it is now) - NA only though. The vacuum line to it give it a vaccum reference, but you'll need a rising rate reg to give extra fuel pressure when on boost.
So for the purpose of getting you running the fuel system is now all good. ;)
You might be suprised just how much difference that 1 coil lead can make!!! :)
The air temp sensor location should be making a huge difference now just to get it running. When it is running and boosting the turbo will be heating to air. Hence causing tuning issues as the ECU thinks its cooler.
What ECU are you actually using?
Next, because you're running sequential injection, did you just wire up the injectors: Out 1 - cylinder 1, output 2 - cylinder 2 etc?????
Because you need to do it in the firing order!!! ie: output 1 - cyl 1, output 2 - cyl 3, output 3 - cyl 4, output 4 - cyl 2.