Do these use the factory bulb sockets, or do I need different bulbs?

These use the factory bulb fitment — your existing bulbs drop straight in. No special bulbs required.

Do I need to remove the bumper to install these?

These mount at factory attachment points inside the headlight cavity. Bumper removal depends on your comfort level — some install without removing it, others take it off for easier access. Either way works.

Are the housings sealed against moisture and road salt?

These are sealed units designed for street use. Check the seal integrity after installation and inspect periodically if you're in a heavy salt environment — normal maintenance for any headlight assembly.