Will this bolt straight into my existing door without modification?

Yes. It mounts at factory rocker points with no drilling or panel work needed. Line it up with the existing holes and secure.

Do I need to match paint, or does this come finished?

This arrives in hard panel form. You'll want to sand and paint it to match your door color before installation—test-fit first to confirm alignment, then remove and finish.

Is this the same size and shape as the OEM handle?

It's designed to fit the same mounting points and match the OEM profile. The keyhole is absent, so if you're upgrading to a different locking method elsewhere on the vehicle, this gives you a clean look on the door.