my only gripe with phase 3 was the difficulty on a few quests. very maat'esque with little room for error. except that we are talking about low level content here. the one with the chocobo egg was obviously trying to teach you something. but the one with the gargoyle and the masked mage was infuriating. made more so by the fact its a 2 part battle.
If your using the armory system and setting the right abilities (like Protect and Cure) these fights aren't hard at all. As long as your letting the main NPC beat on the boss and you focus on the adds, its pretty simple. For the gargoyle/mage fight, you have to focus and kill the Gargoyle first because he has way less HP, but does much more damage. Also, you have to pay attention to his TP moves, and the mage's spells. The difficulty is appreciated, because as you've said, each fight is trying to teach you something. I think it's refreshing to actually have to learn strategy for fights instead of the 99% faceroll content in MMOs these days. Yes, if you just run in guns blazing, you will get your ass handed to you, but if you follow some pretty basic rules (don't stand in the big glowy circle thingy) they're not that challenging.