I like where your head is at but I don't feel it is enough people would pick it over top tree. It needs an ability to synergize with Phoenix dive to give incentive to be in the air. Bottom tree should have an ability to like lion ramparts that allows you to hip fire in air without cancellation of the jump. The melee, like a lot of melee in destiny is not nearly interesting enough. I think changing it all together into an ability like devils ruin would be a great addition to the tree. Hold down melee to charge it into a focused ranged fiery beam. Your idea to improve Phoenix dive is bang on. Needs an overshield cause you are exposed as hell in the air.