the crimp doesn't need more than tack welding, that's all the factory did and little of it - some of the zinc paint is called 'weld-thru primer', so yes, but avoid breathing the fumes!
the flap wheel is 'not enough' - good for many cleaning chores, but getting to clean metal for welding a grinding wheel is best, should be easy to find the mount to put one on the DeWalt
like thisfor doing metal work you can never have enough vise grips, welding clamp style and various size C clamp type especially
Bill