Im in the same boat, I "was" on my parents insurance(Tricare) when i got surgery on 8/4/10 and i got dropped on my 21st birthday which was 8/29/10 so i am only a couple of months in but so far so good.As a matter of fact i just signed up today for insurance through my employer. As far as having future issues i.e. removalcomplications i wouldn't worry to much about that because the lap-band is lower risk. Your first couple of fills should be covered under the original insurance approval meaning they don't re bill your insurance for the first couple of fills.
Also i believe in Obamas health care program he extended the time young adults can stay on their parents policy to 26 years old, and you don't even have to be going to school anymore to receive coverage. Unfortunately for me the haven't passed a program for young adults who's parents are in the military!
Anyways I recommend the lap-band specially because we are young and have a long road ahead of us, and i personally don't want to be stuck with the complicationsproblems that come with the gastric surgery and that are non reversible.
Good Luck!!