MP, INT for nukes, magic acc for enfeebles/nukes, MND/INT both factors into debuffs. MAB obviously for nukes. As a side note also useful for aelioan edge.
Now the main reason i love this hat. The enfeebling casting time -8%. Honestly, i'm not sure if it applies to recast but i highly doubt it.
That -8% is god damn noticeable for any red mage who solo's. Add in more fast cast gear if you can, it's awesome.