Congrats on the new pistol. I am a fan of single action autos.
The X-grip mags are factory mags but with the X-grip extender, right? I cannot see how the mags could cause a light primer strike (note: FTF can mean failure to feed or failure to fire). It could be ammo specific since these occurred with PMC ammo only.
Two "jams" doesn't tell us a lot -- failure to chamber (needed a nudge to chamber)? Stove pipe? Double feed? Sometimes these are resolved with a thorough break-in. Sometimes these are mag related which I would suspect since they occurred with the 7 round mags. Kahr 7 round mags are known to be finicky in their PM9/CM9 pistols.
In any event, I would put enough of your chosen defense rounds through the gun to make sure it is 100% reliable with that ammo and that mag(s).
Jim's Rules of Carry: 1. Any gun is better than no gun. 2. A gun that is reliable is better than a gun that is not. 3. A hole in the right place is better than a hole in the wrong place. 4. A bigger hole is a better hole.