Well your raid is not caster friendly... Missing out on Arcane Tactics and FM with a spriest and a boomkin in the group probably negates the gain you get from the mage being Fire.
Oh Ultraxion your spriest probably could have squeezed in a couple more Mind Blasts and on other fights there are even more he could get in. I'd check with him to make sure he has some notification letting him know when it is off CD. He is probably just not mashing the button quick enough. His DoT uptimes look good though.
For Warlord Blackhorn I'd check to see if he is multi dotting as much as he can. His damage done to targets seems a bit low.
Overall it looks like he is mostly doing things right. He desperately needs 43 more haste though to get to 30% haste. He also have a few misses in those logs so he should probably pick up some more hit as well. If cunning of the cruel and unbinding will drop give those to him as well.. his current trinkets are pretty bad at this point.