Just speaking for myself, but I would never re-use brake pads. But that’s an inherent distaste at running into the possibility of potential problems. An individual can do what they choose to on their own car but in a shop setting one does not want to run the risk of a comeback; which is mechanic speak for a problem due to the reuse of parts and which means a re-do by the mechanic for free.
You might also consider that the vibration could be caused by looseness in a wheel bearing, suspension, or steering component.