Will sleep apnea surgery cause problems with swallowing, speaking, gagging, or sleeping? i.e. what side effects will the surgery possibly have?

Can: I am not a surgeon, but any surgery can have side effects- some short term, some permanent. I would consider getting a couple opinions before having the surgery, or possibly try some other less invasive alternatives, like an oral sleep mouthpiece.

Not usually: In the short time right after surgery you will have some discomfort. The rest depends upon the surgeon and the extent of the surgery.

Anatomy: The anatomical abnormalities that result in OSA can cause those problems. Surgery can help. Seek consultation from an experienced sleep apnea surgeon.