dont have a good dB level for benchmark, but the typical rule of thumb is: as low as possible at rehersal, as low possible stage volume, and a FOH audience experience that suits the room/energy/muisc style. Put as many instruments though the PA as possible. Live performance is all about what the audience hears. The performers just needing to hear what they are doing enough to put on the show they have rehearsed. With some crafty amp positioning, you can dramatically reduce the stage volume and achieve this pretty well. Earplugs are always good. You really get
used to them quickly.. especially if you always rehease etc with them in. Have some recommendations on plugs if you are looking for some real use opinions. Let me know!