Could badminton, or similar exercises like tennis/racquetball help with wrist pain or carpal tunnel?

Carpal Tunnel: The theory with exercise is to "work out the pain, " like many pro athletes do. But the inflammation from the repetitive wrist injury needs to be addressed, which is why the pro athletes combine a regimen of therapy and exercise. Nsaids may reduce the inflammation and ice the area after exercise, and see if that helps. Otherwise, you may not be able to exercise until you tackle the inflammation.

Badminton: It could help with conditioning. As far as wrist pain, if done correctly you can improve tone, flexibility, and strength. If done incorrectly, may create tendonitis, cause sprain, etc.

Probably not: Strenous and repetitive activities can exacerbate the symptoms of carpal tunnel syndrome. Rest and anti inflammatories will help.