I would recommend filing and sanding it smooth, then touching it up with the closest matching paint you can find. That’s likely the best option besides replacing the wheel.
Exactly. There are epoxy spray enamels specifically designed for aluminum alloys, or you can just use Testors enamel from the small jars.
The only way to completely fix curb rash this deep is by replacing the wheel.
Is it removable? You should ask the manufacturer for another exterior lip. Clean up the rest; there are shops that can handle the work.
The damage is already done, big guy.
The question is whether it’s worth the cost to get new wheels.
You could file it down and make it smooth, but that requires skill, and it will likely end up looking worse than it does now.