Do these bolt straight into the factory fog light openings?

Yes. These mount at factory rocker points without drilling or modification. You'll want to test-fit before final fastening to confirm your bumper trim alignment.

Are the LED bulbs included or do I need to source them separately?

The LED projector assemblies come as complete units — you're not buying empty housings. Installation is straightforward once you have the assembly in hand.

Will I need any wiring harness or am I tapping into existing fog light circuits?

Wiring configuration not specified — have your vehicle's service manual handy and test continuity on the existing fog harness before connecting. Consult your Super Duty electrical diagram to confirm switch compatibility.