Prior to reinforcement, any cracks should be "stop-drilled) (drill about a 1/16" hole, centred on the end of the crack. A centre punch is advisable) and plug-welded. Simply welding up the crack will not be much help, since the crack can continue. (This same technique is used for welding up cracks in castings - like the cylinder head or block deck.)
If there are any creases in the metal after it's repaired, I'd suggest stop-drilling the ends of the crease (it's a stress riser) and welding, then reinforcing behind it if you are so inclined.
(As far as this "being accidentally moved to the wrong place" - it isn't. Is this not bodywork?)