How many microarousals are normal during a sleep study? I had 314.

Varies. Micro arousals can be attributed to many causes. I would rely upon my doctor whom ordered the sleep study or the sleep specialist who evaluates the study to provide you with the best info for your questions.
Depends. But that sounds like way too many. Without seeing the report comment can't be made. You should make an appointment with your doctor or a sleep doctor as it sounds as if you have a problem, but it depends on the report, kinds of srousals in one slept.