A PPI is a most but also I have found that you need to be very specific with most shops about what you want checked. I know with one of my Carrera's it passed a PPI w/o checking the valve guildes because I didnt specify...big mistake and I paid dearly soon after.
Although the issues you mention should have been spotted IMO by most "expert" wrenches.
Doing a PPI with the former owners mechanic does not always make sense for obvious reasons. If the former owner stills uses that wrench unfortunatley he isnt going to seek issues to possible hurt the deal.
All said, heres my advice...crack open a cold one and take a deep breath. Top off the oil, clean it up and sit back and start enjoying the car. Unless you can or want to return it, nothing you can do about it now.
Find a reputable shop and take it in for a leak down, compression test or anything else you may be concerned about (I live outside Philly and can recommend some shops). Be prepared, even with a great PPI there is something in there that will need to be addressed soon or later. (Welcome to the club)
Once sorted...drive it like you stole it and start smiling!
