I'm still not quite sure where the sweet spot is on INT VS MAB, but for the most part I've been able to stack as much MAB as possible on EXP level mobs without running into resists much.
The only thing I'm missing from this set is Yigit. http://ffxi.allakhazam.com/profile.xml?197875
And that seems to do really well on all the stuff I've been nuking. There's upgrades to make, and I did some math and found that for RDM (Specifically Elvaan) Zenith Mitts +1 barrely
beats Yigit and loses on MACC.
Now if you are fighting resistant mobs, you'll want to stack as much Elemental Magic Skill + INT as possible. Some changes you can make to your gear for fighting higher level mobs would be: Wizard's Earring
when you are /BLM. Errant Cuffs
(30K gil I think)
Upgrade your rings, +4 INT is cheep. Druid's Slops
are a cheap source of +5 Ele Skill, but I don't know if it beats Mahatma or Errant.
And aside HQing the rest of your gear, or some harder to obtain Salvage/Dynamis/Sea/Sky stuff the rest looks good.
It also looks like you are afraid to lose some MP in your Elemental Magic set. Try making 2 macros for it. One for when you have max MP, then when you've depleted your MP by say half, another macro to switch out all your +MP gear to purely INT/MAB/Elemental Magic/Macc etc...
I'm sure lots of people can be more help than me, but that's a good start I think.