The elephant in the room is ability to pass AND maintain the CAAC medical.
Good luck with this, unless you are a current astronaut.
Very much not true. One of the guys at my airline is clinically classified as morbidly obese and still has a CAAC medical. We have guys who have had heart attacks in the past. We have guys who have had LASIK. The medical exam is extensive, but for the most part not unreasonable. At times they may be a bit goofy over some small things, but it is not too hard to get through for most people. Put it this way, if I can pass the CAAC medical, most people can.