I just posted part of this this on the previous message this morning but it seems to apply to your questions as well....
I had motility issues as well, but mine turned out to be the result of the HH. I am not an expert as far as motility goes, but in my case part of my stomach was above the diaphragm and the LES was not able to close. In effect, I could swallow, but when the food reached the LES it would free-fall from there. During the Barium swallow X-ray/fluroscopic tests, the Radiologist could see the Barium refluxing back into my esophagus when he moved me from verticule to the horizontal position. He diagnosed a medium sized HH and referred me to surgery. Shortly thereafter I had the motility swallow test.
During that test, everything went smoothly the first time but the readings were all screwed up. The probe went down the first time without a hitch. However after it was down, the technician had to fish around quite awhile to try to get it to what he thought was the proper depth. The next day I had to go back and do it all again because the Gastroenterologist who evaluated the test knew something was wrong with the readings. He suspected that the probe went down until it hit the upper part of the HH and curved around and started back up. As it turned out he was correct.
He conducted the re-test himself and had his entire Gastroenterology staff as an audience.......naturally it did not go smoothly....I barfed and gagged the whole time....but he recognized when the probe started to curve around again and managed to fish it into the proper position.
By itself, repairing the HH could have eliminated the problem. However, in order to prevent recurrance, they insisted on also doing the NF wrap. I really was worried about that part of the operation but it all worked out fine. I had an easy recovery and have been symptom free since the repair was done in March of this year.
AS far as the operation for the wrap goes, the dangers you mention are already past when they repair the HH. They have already invaded and "insulted" your abdomen as much as they are going to just to gain access to your esophagus. They do the wrap on the way out. I dont want to minimize the proceedure...but in my case, the wrap was done as insurance to prevent recurrance. They put three sutures in the Hiatus of the diaphragm to reduece the size of the opening. By doing the wrap, they increase the diameter of the esophagus--just like installing a bushing!!! That also causes the contractions of the stomach during digestion to help the LES close off the esophagus to prevent stomach acid from leaking into the esophagus.
As I said above, I had both the HH repair and the wrap and had an easy recovery--and I am an old "dude"--73 when I had the operation......I was blessed being back to my normal routine in three weeks.