Of all the doctors that I have seen over the years, not one has relayed a limit on my age because of NF. I have dealt with many doctors at UCLA here in Los Angeles, who are trained in NF and have med students that some day may find a cure. They revere me as a study specimen because the doctors always find a way to have them take a look at a real person with NF vs. just the text book. I believe I will live as long as I can so long as I eat healthy, keep an eye on my tumors and stay positive.
We could all be wiped out tomorrow by a catalismic event tomorrow regardless of NF or not. So live life to the fullest for as long are on this planet, the ultimate decision of our demise is not up to us.