Do these attach using factory rocker bolt holes?

Yes. These mount directly at the factory attachment points on the rocker panels — no drilling, no frame work needed. Standard hand tools and about an hour per side.

What about hardware — do I get mounting bolts?

Hardware is not confirmed in the product specs. Have your fasteners and any sealant on hand before install; test-fit the boards to your rocker points first to confirm what you'll need.

Will these interfere with my suspension or undercarriage?

At six inches, they sit above the suspension travel and clear typical bumps. If you've added a lift kit or lowering springs, test-fit to confirm clearance before final install.