I have had ALL of these symptoms. Don't know anything about the vagus nerve, but would be anxious to learn.
The acid reflux, shortness of breath, and fluttering feeling in the chest are not "classic" symptoms of MS. Supposedly. MS specialist is not interested in hearing about these symptoms, because they are "not related to MS." Plus, these symptoms are so trivial, vague, and hard to prove. You end up sounding like a hypochondriac if you bother to mention them. There is much more serious symptoms to deal with. Maybe that is why they have been ignored as symptoms that MSers have.