A mother-son road movie more laced with humor than laden with trauma, Hot Water marks a warm and sensitive, if not entirely satisfying, debut feature from Ramzi Bashour. There’s an undeniable familiarity that nips at the heels (or wheels?) of the film as it traverses classic American landscapes alongside its protagonists, a tightly wound Lebanese woman (Lubna Azabal) and her turbulent, U.S.-raised teenager (Daniel Zolghadri). We’ve been here before — in this situation, with these types, against these backdrops. Every year at Sundance, to be exact. Hot Water The Bottom Line Warm and sweet, if not entirely satisfying. Venue: Sundance Film Festival (U.S. Dramatic Competition)Cast: Lubna Azabal, Daniel Zolghadri, Dale Dickey, Gabe FazioDirector-writer: Ramzi Bashour 1 hour 37 minutes Luckily, the leads are good company, and there’s just enough in Hot Water that feels fresh and personal to lift it above dreaded indie staleness. Bashour has a light touch, an aversion to exposition, histrionics and overt sentimentality, that serves the material well. If the film’s modesty, its glancing quality, is a strength, it’s also a …