Well that PLD sounds like a dick, but what do you expect; those types of players exist.

As a WAR I am going to say that how you should heal is very dependent on the attitude/playstyle of your tank.

If you have a very aggressive/unpredictable tank, you need to keep them topped off as much as possible so that they can keep moving and not be worried about waiting on that heal before moving to pull the next group of mobs.

If you have a laid back/predictable tank, then what you are doing is fine.

Personally I am very aggressive as a warrior. I usually pull 2-3 groups and have DPS AoE them down on my AK runs. If I had a healer who didn't keep me topped off to the best of their ability, I wouldn't be confident moving ahead and keeping a steady flow of mobs coming for our DPS to AoE down.