I'm having a bit of trouble getting Belial down in Hell difficulty as a Demon Hunter. I'm level 58, with 6.3k damage, 12k life and 1630 armor. I'm using Smoke Screen with Lingering Fog, Caltrops with Torturous Ground (changing to Vault with Tumble when he enters the last phase), Hungering Arrow with Cinder Arrow, Multishot with Fire at Will (changing to Preparation with Focused Mind when he enters last phase), Bola Shot with Thunder Ball and Impale with Chemical Burn. The passives are Tactical Advantage, Vengeance and Steady Aim.
My problem currently is getting through the second phase, when Belial is moving and his minions start spawning as well. Granted I'm not a spectacular Diablo player, but I still think I should be able to kill him with some ease. I'm not sure if I'm doing something wrong, if I'm using the wrong abilities or if I'm just undergeared. Could anyone give me some advice?