Los Angeles painter Matthew Heller is on the verge of making it big; the thick lines and vibrancy of his trademark lexicon of sensual, roughly-formed nudes in silhouette have garnered increasing attention from critics and collectors, and inspired near-fanatical devotion among his fans. Which is why his most recent show, “Everything is a Love Story,” is so refreshing. Half a dozen mini-series riff on aspects of romance, his enduring topic, and in each of these he takes a fresh risk. The expansiveness of his technique indicates an earnest desire to push his own boundaries and leave