As far as the seam goes, the rim could be straightened. But from the pictures it appears that there are deep grooves cut into the braking surface. And since the rim suffered a fairly large impact I would guess that a larger part of the rim may be "flattened".

I suspect that the rim needs to be replaced but can't really tell without seeing it. Spin the wheel slowly on the bike close to a fixed object and see if the wheel is still round.

If the grooves are as bad as they look I would definitely replace it.

I also suspect that you need softer new brake pads. I like KoolStop salmon colored pads.