Does this need any bolts or fasteners to install?

Mounting hardware is not included with this bracket. You'll need to source fasteners appropriate for your vehicle's factory attachment points — check your owner's manual or local hardware supplier for the correct bolt size and gauge.

Will this bracket work with a front bumper I already have installed?

The bracket mounts at factory points, so compatibility depends on whether your bumper covers or interferes with those attachment locations. Test-fit before committing to final installation.

Can I use this bracket on a vehicle with a front splitter or lower valance?

Your splitter or valance may block access to the mounting points or sit in front of where the bracket sits. Measure the clearance between your current front end parts and the bumper trim before ordering.