2005 Chrysler PT Cruiser PT Dream Cruiser Multiple problems

Initially when I borrowed my in-laws car, it would not blow cold AC. My father in law is an AC tech for residential/commercial, so he put a two cans of R134A into it but when he did it he turned the can upside down to get the fluid in there quicker? Anyways, it had blew cold air for about a day. It sat overnight and it seemed that it would be all gone. I put more refrigerant into it and the same thing happened. Can I find the leak by some conventional method?

Also, when driving the air got warm in the car on about a 3 hour drive. When stopped the car's A/C would keep cycling in 2-3 minute increments then the car would start surging at the same time. One time it actually shut off in traffic. I am assuming that these are related. Then about a week ago it was about 30* outside and the car's idle dropped at a stop light and it bogged down until shutting completely off. So now when I pull up to a light and the car is just started I put it in neutral because the idle begins to drop sometimes.

There are no check engine lights and no codes in the computer. The only lights that are on are a ABS (for the faulty RR) and an associated Traction Control Light.

Any suggestions?

Thanks ahead of time,
Gus