Do I need to drill holes in my bed for installation?

No drilling required. This cover mounts directly at your factory anchor points — test-fit the brackets first to confirm proper alignment with your specific bed configuration.

Can I open just one or two panels without removing the entire cover?

Yes. The tri-fold design lets you prop open individual sections for partial access to your bed. You don't have to remove the whole cover if you only need to reach the front or middle.

Does this cover seal against weather, or is it just for looks?

Soft tonneau covers provide weather protection when fully closed, though some water may seep along the seams in heavy rain. Expect it to reduce wind noise and keep light dust out, but it's not a waterproof seal like a hard tonneau.