IMO, 3 (or 4) is the way to go. I agree that the lounge, as it sits right now, is too cluttered with Watering Hole threads. There are too many devices for the Lounge to be cluttered with these.
IMO, it would help keep off topic out of the device forums and yet still allow it in the device forums.
Option 3, IMO, is the BEST option available.