Some panels have all the gauges in one gauge file. How can you open up this cluster of gauges, so you can add or remove some gauges?

Why would you want to do that? You don't need to use all of the gauges that are included on every panel and you can add other gauges indiviually to any panel. So if there are extra gauges that you don't use, so be it and don't worry about it, they don't hurt a thing. R-