A convenience store in Skid Row is changing hands from the community-oriented Korean American family that runs it — to a Black-led nonprofit. “Existencia,” a new work by the experimental performance troupe Diavolo, explores the chaos and community that resulted from the 1994 Northridge earthquake. In an era of “hurriquakes,” heat waves, and fires, The Academy Museum screening series “Beware the Elements! Natural Disasters on Film” looks at the real-world implications of disaster films.