I got in a little bit agao and am a bit heat fried. This one I can answer quick.
Correct. The 4 pin ECU does not use the 5 Ohm resistor. I don't think it makes a difference if its phyically removed or not -except if removing it means loose wires, then leaving it there is better.
The 5 ohm was originally used to keep the ECU from drawing too much current. I've not figured out how internally that worked. Someone with more knowledge and experience with transistors and circuits probbaly could if they were interested enough. But the bottom line is you don't need the 5 Ohm.