Have put over 200 rds thru my new PF9 and had just 1 FTE. Zero FTF. Ate winchester white box and federal without issue. I have big hands and thick fingers and my trigger finger got beat up a little against the trigger guard but no issues w/ my palm like some have complained about. Little rust spots inside don't seem to be growing so it must be something from finishing process. Overall, I am VERY happy with my new purchase.
I'd contact Kel-Tec about the slide finish, let us know how it goes.
I would just have it refinished, look into duracoat or something close.