SIGNIFICANTS AND OTHERS, Cobalt Ensemble Theatre, at TinFish Theatre. With its debut production, Cobalt Ensemble Theatre is already lost in the crowd of unremarkable storefront troupes. Assembling “a collection of comedic vignettes about love relationships” (a concept about as broad as “six pop songs about sex”), director Katherine Condit-Ladd keeps everything light and forgettable. With the exception of the final piece, David Ives’s farcical The Universal Language, these vignettes are nearly indistinguishable: all include a quirky setup (a man shaving his ex-girlfriend’s legs, a married woman desperate to cheat on her husband), lots of irrelevant quips (“I have fish–I’m working up to pets”), a psychological imbalance between two people that comes gradually to light, and a facile, faux-poignant ending.