We All worry about this kinda stuff......... you are normal.
There is a really good thread on the pre-lap board that really addresses many of your questions (it might be burried a little bit, but look for it, it has about 2000 reads last time I checked. and it is written by a successful bandee to people with just your questions.) LET ME KNOW IF YOU CANNOT FIND IT - it is a wonderful post.
As for everything else, take it one day at a time, one question at a time. I called the doctors office to talk to them CONSTANTLY about my fears - they had one particular person who dealt with calls like this and gave advice. And later, after surgery, she was the one who told me that either everything was normal (many times) or that I needed to talk to the PA about this situation (only once, and he took me off a med that was too strong for my stomach).
Before surgery: I FINALLY settled down and relaxed when I was patiently told that it was a 45 minute out-patient surgery. i had somehow built the surgery up in my mind to something bigger than it was.
After surgery: I have had my bumps: an overfill and intolerance to a med (raging diarreah - ew); And I still could have a problem - but seriously I am off my Blood Pressure meds (122/80 today) and no cholesteral meds anymore ......and I am not even half way an my weight loss journey. It has been wonderful--for me. I now longer agonize on how and what I am going to eat: the answer is anything I want that I can tolerate in a small portion.
BUT: you must decide what is right for you: ask your questions and demand answers: I was truly pissed when I was told i would have to give up diet coke and wanted (DEMANDED) to know WHY- which I found out- and now I don't even want it. Also, I was pissed when I found out that you have to go back on liquids for a few days after a fill.......at my first fill. (I thought someone shoulda told me earlier )
Good luck, Terri