I agree with bigcountry, but would like to add a few things. Answering your original question, the answer is YES. The string creeping over the years could be causing some of the problems. Usually arm slapping is due to what he said, too much bow and/or hand position. It can also be a symptom of too long a draw.

The thing is, all of these could be caused by the string
stretching". As the string creeps the draw length gets longer and the weight goes up, both of which can cause bad changes to shooting form.

It's easy enough to measure things and find out if this is the problem. Measure the A2A and brace height to see how they compare to factory advertised specs. If the string has crept appreciable then the A2A will be long and the brace height will be low.

And I would note that 5 years is too long on strings if the bow is shot much. Especially if they are PSE factory strings.