Will this bolt straight to my bumper, or do I need to modify anything?

It mounts at factory points with no drilling or cutting. Test-fit it dry first to confirm alignment, then secure with the fasteners that work with your bumper tabs.

Does the matte black finish need primer or clear coat before installation?

The finish ships ready to install. If you're planning to polish or repaint down the road, light scuff with 400-grit and primer as you would any panel.

What if the grille doesn't sit flush when I bolt it on?

Check your bumper for impact damage or warping first. If the bumper is straight and the grille still gaps, loosen fasteners slightly, adjust for even spacing, then retighten.