Crystal Block +45% on OH will help your defense a lot. and you only need 1 Crystal Luck & Gold Find. if you are on Mythic 3 Difficulty, you only need to get +300% on your items for Gold Find & Luck to get +650%, +850% with Fortunate Perk (you have 
), and +1012% with Epiphany (5)(which you also have ).
for Gold Find & Luck, if you keep 3x Greed Natures, change the other 3 to Luck. this way you can get rid of the Gold Find on your Pet. or if you keep your Natures the same, change the Gold Find on the Pet to Luck instead.
1x Epic Crit Chance and Crit DMG instead of 2x 5000 Fire DMG. more Critical Hits for even more Critical DMG!!! 
since you have Taunt, change Twister on your Gauntlet to Storm, it is a better combination. especially with Crushing Flames. Twister goes away from the monsters you Taunted, and Storm does more DMG and has a higher Attack Frequency when you put Hero Points into them.
add 2x Epic Storm instead of 2x 5000 Fire DMG. Storm 40 is 8 attacks a second for 5 seconds. Twister 40 is 5.6 attacks a second for 2 seconds. Twister needs lots of Cool Down to really be useful, but Storm only needs enough Cool Down to be used every 5 seconds, which is how long the Spell lasts.
with 3x 5000 Fire DMG left, change one to 1x Crushing Blow and the others to 2x Crit DMG (with your Epiphany (5) and the Crit DMG you added earlier, your Crit DMG is now +438% instead of the +225% you have now).
I know you are thinking I am crazy making you take off 7x 5000 Fire DMG, but with the 2x Storm, more Crit Chance & DMG, and a little more chance for Crushing Blow to improve the DMG of Crushing Flames, you are actually doing a lot more DMG, and the Crystal Block will help you with survival.
I don’t know if this will help, but change Amplify Talent to Sorcery. with Legend +30% Elemental Crit, you now have +50% Immolate for your Skills, which means more chance for Crushing Flames to work. all of the other changes that increased DMG might make it easier to change Amplify to Sorcery.
I used a Storm & Taunt Build while Ascending for Perks, and for farming for awhile, so I know that it works good. I didn’t have so many Farm Sets, which is why you need other ways to make DMG.
I hope this helps make farming easier and more fun.
Edit: I just did some calculations. although taking off all seven 5k Fire lowers your Normal DMG, you are doing more DMG with Crits. and improving your Crit Chance from 45% to 55% also means more Critical Hits.
I used a pretend weapon that does 10k dmg, and used +200% WD, 5k WD, +200% ED, +35k ED, x4 (for Twister DMG), +100% Twister (20 Points in Twister), +50% crit hit dmg, +225% Crit DMG. this is a similar to what your Build has right now. a crit hit with this came out to 5,460,000 DMG.
with my changes, it is a 10k Weapon using +200% WD, +5k WD, +200% ED, x4 (for Twister DMG), +200% Twister (40 Points in Twister), +50% crit hit dmg, +438% Crit DMG. a crit hit with this came out to 10,168,200 DMG. umm, Storm does x6, so the DMG in the end would be even higher.
(in Mid’s DMG Guide, the base +50% Crit DMG is added to any other Crit DMG, so the +50% & +225% would be +275% for the first and +50% & +438% would be +488% for the second. the new numbers are 4,200,000 DMG & 7,408,800 DMG Crit DMG. even though lower, the second Build still does more DMG. my head is starting to spin). 
DMG from Crits will totally make up for loss of Normal DMG without the 7x 5k Fire DMG.
I was just wondering if the changes really made a difference, so I took a look with a calculator! 
these calculations also didn’t include Power Stat, Glasscannon, or Amplify. or Energy? also, attacks do +/- 25% for a DMG range. like 75-125 DMG for a weapon that does 100 DMG.
hope this helps.