I dont have a problem taking PLD over GLA and have experienced the issues with running out of MP, however..

I personally have found i dont NEED to be throwing cures to keep hate and i dont use holy succor specifically for hate generation.

My philosophy is:

build hate with sentinal-> Provoke, flash, war drum, ws's, rampart

Increase party survivabilty with holy succor and divine veil. I imagine if i have pugs and drgs around me eating aoe they would be thankfull for a regen from divine veil.

I find that the whm over cure me anyway and by the time i finish casting holy succor it cures for 0, so i save it for other party members which are less likely to get a cure so quickly from the healers.

and tell me poping Hallowed ground when the next hit is going to kill you doesnt completely redeem the job

FYI, you can recover alot of MP in the Ifrit fight by putting your sword away and standing still during jumps, but i realise this isnt normally possible.