I make my door handle flanges to fit the radius of the door exactly and weld them on before I cut the tank/ pipe. This will keep the door from springing.
As far as the rest of the pipe.. I always weld the firebox and end caps on before I cut the door. It may or may not do anything to keep it in place, but I have not had the CC give me a problem on any of my builds yet. So more than likely , it must help.
You could push it back in place and tack weld it , then follow the way I do it, or try to bend it with a chain and bottle jack. If it's the cc and not the door, just remember that you have the reverse flow plate to weld in, and that could be utilized to help hold the pipe where you want it also.