Do these bolt straight to the factory mounting points?

Yes. These are designed for factory mounting locations with no drilling or brackets required. Install time is minimal.

Will the switch wire into my existing electrical, or does it need its own harness?

The switch comes integrated with the kit, but you'll need to confirm routing with your vehicle's electrical layout or a service manual to avoid conflicts with existing wiring.

Are the H10 bulbs replaceable, or are they sealed in?

H10 bulbs are standard replacements—you can swap them out as they wear. The housings are not sealed units.