2004 mustang remote start clarification

i am installing a remote start in a friend's vehicle. i have done this sort of thing before but not on this specific vehicle. i just want to clarify some points on the wiring guides i have found on here, through my alldata, and my own testing. i have found that in the case of my door locks, i will need to use a relay to invert the polarity of the signal from this particular RS. i apparently do not need to use it for the trunk release. what i have found is that when i test the wires for the door locks (Lock: LIGHT GREEN PIN 20 OF BLK 20 PIN, Unlock: VIOLET PIN 18 OF BLK 20 PIN, at GEM), at rest my tester finds ground on the wires, and when i hit the switch on the door, it turns to positive, and when i release the button it goes back to negative... is this going to present a problem for me? should i not use these wires? the other part of my question surrounds the GEM itself. i assume that since i find several guides on this site that all point to wires involving the GEM, that they are tried-and-true methods and that using the output side of the GEM's wires is safe. but i didnt just assume that this was ok, i looked in alldata and it appears that most everything on the output side of the GEM is protected via relay, so no feedback into the GEM should be possible. is this correct?

no problems those are the right lock and unlock wires, but if you connect to them at the GEM or in the kick panel, if you think about it, no matter where you connect your lock wires, the signal will always make it back to the GEM ....