You are not wasting anyone's time.
When you are learning you are making the most of time. You understand the injector is a solenoid/ pintle setup that allows pressurized fuel to be sprayed into the intake.
#1 fuel pressure does make a difference on gasoline fuel injection. You clamp off the fuel return and see what happens.
#2 The pulse width modulation (controlled by the pcm) and fuel pressure/volume control the fuel amount going into the intake.
If you are having or think you are having trouble with your fuel injectors contact www.lindertech.com 888-809-3835. These guys can test, flow rate, clean and match/set fuel injectors.