first, Weaken vs Ignore Resist. you know how if a weapons element is the same as the maps all monsters take 50% less damage from it? a +90% Crystal Weaken will do more damage than if you used Ignore Resist, even though only 90% of your attacks will Weaken.
this is the post that explains it.
you could go with Weaken +90%, get rid of the Ignore Resist, put a +10% Crushing Blow on the Pet or somewhere else, or keep the Ignore Resist and Push the Limit, put an Epic Crushing Blow some somewhere else. and do some tests to see if you need to keep the Resource Cost because of the extra resource cost from PtL. also, you would have to Jasper the Item to Warrior to get Rage and then Jasper back to Wizard.
it all depends on how much change the build needs to have the +100% Fire. I would suggest going with the fewest changes possible to keep it as it was while putting in any changes for improvements that wont get you too frustrated in the short term.