hi-was looking for some advice please

i am adding an oem trunk release to my 08 civic. (bought from a model that has this feature)
using a viper 5101 starter aux fob to send signal to pop trunk
wiring to relay

problem #1
not getting negative signal from starter brain. read previous posts-think my red/white wire is fried. it pops when i ground the lead...i thought i heard i could either assign a different wire to send the signal -or-do buss or bitwriter programming? anyone know anything about this? should this be covered under warranty and free from the audio shop who installed the unit?

problem #2
where should i power this relay? its under the dash by the pedals-i dont want to t tap into the red wire. can i use an " add a circuit"? are they limited to 10 amps? dont i need 20?

i also have the green door lock wire and a white wire showing contant power in the harness behind the left back seat in the c pillar. could i tap off one of those?

could i also use the same wire above to add a usb charger for my phone so i can leave it in the car to charge without my keys?

thank you in advance for your time and help!