Do I need fasteners to install this, or are they included?

Mounting hardware is not included with this rail. You'll need fasteners appropriate for your factory mounting points — check your truck's service manual or test-fit first to determine what size bolts work best with your bed anchor locations.

Can I paint this black rail, or is it already finished?

It ships in black finish and ready to install as-is. If you want to match a different color or refinish it, light surface prep with 120–150 grit sandpaper will help paint adhesion.

Will this rail interfere with tonneau covers or bed covers?

The rail sits at the bed opening edge. Test compatibility with your specific cover model before final installation, as some tonneau designs may require slight adjustment to the rail position or cover fitment.