I have also had a pretty mild recovery. I am almost three weeks post op. I was worried as well about my NF coming undone, but everything seems to be doing just fine. I can do nearly everything I did before, except for eat solids. I can barely eat cottage cheese, and I am not swallowing pills yet. It is a little frustrating to me, because I want to be able to eat solids, but that will have to wait for at least another week for me. However, there are some people who can eat solids sooner than me, but unfortunately, I'm one who has to wait.
I wouldn't worry about your NF coming undone. I'm thinking that it is a pretty permanent surgery, and hard to ruin at least with things like burping. You sound like everything is pretty normal, especially for your newness in recovery.
Anyway, I hope you have a speedy recovery.