I think it's pretty much a given that something is
eventually going to break. On my C5 I had problems with the female end of the pins pulling out of the door and cracking the fiberglass, and also some of the male pins broke in half, but it wasn't until the third or fourth time removing the panels that the problems appeared. I used superglue to hold the bases in and purchased new male pins from an online GM parts supplier for half of what my local dealer wanted (shipping included).
I've had the doors apart on the C6 twice now without any problems. My fingers are crossed for my next attempt.
I've read on this forum that most local auto parts stores carry replacement pins that can be used. If you end up needing new ones just take one in and visually compare what they have available.