Cataclysm is the only tree worth using. Most of Motion is about crowd control, and Harmony is about support.
Health regeneration is a lost cause. Nurse class mods don't heal quickly enough to save you, and nothing out of Harmony is good enough either. You're going to have to avoid death by not taking health damage and getting second winds, so get a turtle shield with high capacity and good recharge stats, and don't worry about the health reduction.
Use the class mod for SMG damage and use Maliwan SMGs.