Do these bolt directly to the bumper or do I need to cut anything?

They mount at factory points—no drilling or cutting required. Test-fit before permanently securing to confirm alignment with your bumper opening.

Is the switch dashboard-mounted or dash-integrated?

Mounting method and location not specified in the product listing. Check your Accord's layout and compare fitment before ordering if dash integration is critical to your install plan.

Can I replace just the bulbs later, or do I have to swap the whole assembly?

H11 is a standard socket; you can source replacement bulbs separately. Bulb life varies by driving habit, so plan for periodic swaps once these wear out.