What range you should be fighting on depending much more on match-up than just which one he is good at. He is fairly even at all ranges. Choose your approach depending on match-up, hakumen players need to be able to switch between all ranges.
dmg from jC and 4C are good, but combo dmg are low. They are still zoning tools, and do not rely heavily on them or you would end up capping your dmg output for no reason and also make yourself very vulnerable for being too one dimensional.
ragna is much better from ground approach, while bang is fairly good from either. speed on 6C is slower, 4C is 15F so they are hardly fast moves. The important part is not that start-up frames, but the fact that recovery frames are much better, so you don't get killed for using C moves. That's the main reason hakumen is better.