Just an update. My son has been daily driving this thing for some time now and everything is fine. The finish is still fine too, no rusty looking mess yet.
I am 2 hours south of you MrGiggles in Mountain Home. My son's FS-Ze swap is also running just fine on the stock ECU. You will need to run premium fuel though because of the higher compression.
Well, my son's P5 had a nasty shimmy while braking due to a warped front rotor. All pads looked good but I figured if we gotta do brakes let's just do all of them. After reading some good reviews on a couple other forums I decided for the money we'd give them a go...