Agreed. Looks like your doors are your weak spot right now. I would go about reinforcing everything on them that can possibly give way first. Now that I think on it, hows the roof holding out?
Those cracks seem like a fairly easy fix. Take a die grinder to all the cracks and clean them up really good. Then get a 135amp MIG, turn the heat down, wire speed fairly low (about 3 depending on the welder) and tack the cracks back together, going back and forth to spread out the heat and not distort the metal.
Grind down the tacks, primer, paint. I would say skim coat of bondo too but with the mad flex it would probably break it off and leave it looking nasty.
That imo is the ONLY way to fix that. Not saying a weld wont break but you could prevent further damage with a little reinforcement on the inside of the door.