Sounds like you're doing what you can to make this work.
If you make it through the prep thread, and don't make it run 100%, I think it's time to give Kahr customer service a call.
The extractor mod is really only needed to run certain brands of non-SAAMI spec ammo in it (Fiocchi). If it doesn't run with PMC or Remington FMJ, there's a problem (assuming no operator errors).