[ImperialCrown]

Congrats on the PT convertible. The multiple codes may all be from a single issue. I doubt that 12 things went wrong all at once.
What were the fault codes? You have a printout?
Depending on the original in-service date and current mileage. you may still have the extended federal emissions warranty good for 8/80 that covers the PCM and cat.

 

[ImperialCrown]

You shouldn't have to live with an unreliable car if it has the potential to strand you. 'Keep trying it' is a cop-out and won't change the situation.
The chipped (SKIM) key has an internal transponder that communicates with an antenna surrounding the ignition key cylinder. The PCM reads the transponder code, notes that the correct key is in the ignition and allows the car to keep running.
SKIM keys have a gray body and conventional keys have a black or bare metal body. If it doesn't say 'Chrysler' or have the pentastar symbol on it, then it may be a generic key.
The SKIM feature is embedded and can't be disabled. If it was easy to disable, then the crooks could do it and the anti-theft feature would be worthless.
It may be a problem either with the key itself or the steering column SKIM module.
A good scan tool like the dealer DRB III may be necessary to diagnose this. Bring both keys with you. Get all communication and work documented for your protection if things go sour. I feel that the used car dealer should cover this repair in good faith under your 1/1000 warranty.