4 sets of pads sounds pretty good. My guess is, as well as which pads you use, it will also depend on the conditions you ride in - mud and dust will accelerate rotor wear.
I only got 2 sets of (resin) pads out of the 180mm Galfer that came on my Rise (and it was well under the minimum spec by...
Even the cheapest after-market air forks I've seen have rebound control. I'd throw that in the bin and get a new one. Maybe something like an SR Suntour XCR 34?
Although the fact that it won't work right at 110psi is weird. If anything, the rebound should be too fast at that pressure. They...