The quantity and quality of arts-related talent in Nevada County never ceases to amaze me. For a small area with a small population, we have more than our proportionate share of excellent musicians, visual artists and theater performers. Sierra Stages’ current production of Stephen Sondheim and John Weidman’s 1990 musical “Assassins” provides a showcase and opportunity to shine for some of those fine local actors, singers and musicians, as well as a creative production staff. Because I was not very familiar with this play, I was concerned as to whether I’d like it. The subject matter — assassinations or attempts …