because Items are considered level 20 in Battle Arena, you don’t want to use Weapon Damage % or Elemental Damage % affixes. just use +5000 Weapon damage and +5000 Fire Damage. umm, I guess keep one of the Legend +100% Fire for the Inferno Elemental damage boost. put in some +250% All Resist. put Energy Mythic on another Item and put Unity Mythic on the Ring. with all items being Fire, Unity will cause all of your Elemental Resists to be the same as your Fire Resists. maybe use +400% Fire Resist instead? on your post, your Fire Resist is 436. Unity would make the other Elements the same instead of 151.
here is a post or two that can help in figuring out your damage & DPS for Campaign & PVP builds.