I couldnt be guaranteed if coating my cylinders and/or pipes would effect performance and/or cooling so i didnt.
As for the 7mil with a certain rod helping life, i think of how much run time and abuse grif's old 10mil serval had on it. It help up for an extremely long time. For me, that's good enough.
For the hoses, i still like regular black hose from Napa. It's cheap and it's subtle.