It wouldn't affect all gears for the band to be off, as it would just skip second gear and shift 1-3.
Betcha that drum is tore up under the band and some of the metal went through the pump, converter and valve body causing low pressure and slipping of the direct clutchpack.
A little metal in the pan can be normal depending on what metal it is.
If it sticks to a magnet it's not a good sign, and absolutely ANY burning of anything is a rebuild at the very least.