Steve,
Playing accordion SHOULD be good for you...but an inexperienced player can still find creative ways to hurt himself doing it. As long as you have the benefit of a sympathetic PT, maybe you could ask him/her to watch you play a song or two. You may have slipped into some positions/postures/habits that are contributing to the pain. Maybe you are bending your wrists the wrong way or something? It might also be a good idea to arrange for a lesson with someone knowledgable enough to take a hard look at how you're holding the thing.
Finally, Arriette players are the hardest working people in Cajun music. That box may not be your biggest problem, but it's not helping.
That's my two cents. Good luck!

When I first started playing Cajun accordion, I took off two weeks and did nothing but play for 8-12 hours every day to learn.

In doing so I damaged my wrists and arms so that I now I have to be very careful how much I play. (The doc says I will never recover from this)

The PT said that in my case, the accordion playing was making things worse, not building endurance. The combination of working on a computer and playing the accordion was deadly!

A better accordion will make it easier to play, and lightening the button spring tension will make a difference in your ability to play for long periods of time.

But, as others have said, "A good workman never blames his tools". A better accordion will not make you a better player.

One thing that may help is to think about the tension in your arms, hands and fingers as you play. When you are learning, there is a dendency to add extra tension. (hold the accordion too tightly, push buttons harder, pull bellows in a rough or jerky manner)

The less tension you can learn to use while playing, the longer you will be able to play, even on a "cheap" box.

If you have ever watched people like Steve Reiley play, you will notice that it looks like he is using minimal effort to play, but is playing very fast and intricately if you listen to it.

My favorite Steve Rieley quote seems appropriate here, "I used to have to work hard to make it look easy, now I have to work hard to make it look hard."

DP

I learned on an Ariette, to later purchase two LA handmade. There is a huge difference in terms of the energy and strengh to operate an Ariette vs. a good handmade. The handmade sure won't make you a better player, but playing will definitely be much easier. Lighter spring system, faster button response combined to air tight bellows do make a huge difference. If you'd like an event lighter and faster response, you could consider a hand Quebec-made. Some that I've tried can almost play by themselves
You could get one for about $2,000 Canadian dollar)from one fellow I know. Bottom line: If you really enjoy playing, get a good box (Louisiana or Quebec handmade).
Maz

Thanks to all of you who responded to my questions. Sorry it took a while to reply.

Steve: I kind of see it as needing to have the right equipment since I do have limitations that will in all likelihood be present no matter what. I’m just looking to make it as easy as possible for myself. Plus it’s hard to get better with such limited playing time. Playing Cajun/Zydeco music doesn’t seem to be an option but something I have to do (sure none of you understand that).

Ed: I am going to talk with the guy that fronts the local Cajun and Zydeco bands about playing his hand built accordions before I go forward. I can be pretty patient and playing actually helps my spirits while I learn how to live with the pain and limitations. The music seems to be in my blood.

Claude: I actually played for my PT and to my surprise avoided a lawsuit for pain and suffering. He said technique looked good from a PT point of view. I am going to arrange to take a lesson with someone here in town just to check things out.

DP: Sorry to hear what happened as you were learning. I can certainly be prone to unwise enthusiasm but my current circumstances provide me with immediate and dramatic feedback if I fall into that old habit. I agree with what you say about the tension issue and that’s actually gotten better over time. I know the only thing that will make me better is to play. I’m just looking to create the best circumstances I can for making that happen.

Maz: Thanks for the ideas on purchase options. Let me know the person you have in Quebec since it may be easier for me to pay a visit to him.

Bottom line. Thanks for the thoughts and it looks like I’m headed for a handmade box.

If I were you and I was on the market for a good quality box, I would jump on this one on EBAY and do the BUY IT NOW option. See link above. This box is worth over $2K- $2.5K. I will get back to you with my Quebec contact within a couple of days. I am in the process of moving my office, and my business card rolodex is somewhere in a box. Ciao. MAZ

Maz, Yeah I'm looking at it. Hate to say it but I really like the look of wood so this doesn't fit in that way but may be too good of an opportunity to pass up.
Steve