[Juggernaut] Fire/Burning Damage?

[Lillis]

So, I decided to build a Juggernaut (Defense + Earth) despite the fact that Earth Mastery is currently bugged (IIRC it was stated by some dev that it should give DEX bonus as well). He's using Hephaestus' Mace, Shield, and two Rings. And along with that Peleus Armor, Conqueror Helm and Boots, Phobos, and Aphrodite Amulet.
So far I have 250 base STR, and 250 base INT (just enough STR for gear and rest in INT for increase in Fire/Burning Damage). However, I'm not sure the large amount of +XX% Fire Damage I'm currently sporting actually applies to all the Burning Damage I have? Does it?
Advice on other aspects of this character are welcome.
Thanks in advance!