For the bent rim, remove the tire and try to use blocks of wood and a large bench vise to press it back into shape. You do not need to ose blocks which are shaped to fit the wheel, just try to suppert it where it is ok and apply pressure to the center of the kink. Go slowly, if the wheel cracks, replace it.
For the cracked rim, if it is still true, check it regularly and either replace it or have it welded if it spreads.
For future pot holes, if you can think of it and react in time, stand on the pedals with your knees bent and try to tug up on the handlebars as if you were climbing a kerb.