What you've said is correct on alot of accounts, about the new spells being MP-drains, and the aspect of drawn out fights.
The only thing any of us can do is make the most of every situation. When you're idle, have on all your refresh gear, including the weapon, and have refresh casted on yourself. When you're nuking go for the epeen always. I'm not saying to AM2 all the time - stick with the tier 3 and 4 but build up your blm to be lethal so those lower tier spells are brutal and you save MP. In the end, you'll find the mob looking hungrily at you and as you feel the jaws of death clamp around you when Mana Wall wears out you can close your eyes and smile... until you remember you forgot reraise. But ah well