Do I need bolts to install this, or does it come with hardware?

Hardware is not included with this mirror. Source bolts that match your vehicle's original factory mounting — your service manual or local hardware supplier can confirm the size and thread.

Can I paint this mirror before or after installation?

Paint after installation. Once mounted, clean the surface, apply primer, and topcoat to match your truck. This prevents chipping during the install process and ensures a uniform finish around the seams.

Will this fit if I already have an electric mirror on the other side?

This is a manual mirror only — no wiring or motor. It's a direct bolt-on for the left side, but mixing manual and electric mirrors is purely your choice functionally.