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An interesting trait about the Blue Mage is it's omnious learning capability can by limited by choice or DM rule to specific themes. So like many superheroes, mages in entertainment, and so on, you can have an nearly unlimited usage of a certain scope of powers.
For instance, Naruto has two real powers, clones and the Rasenga. Ichigo has super speed and a blast ability. Starfire has lasers and flight. Wolverine has claws and regeneration. And so on, these heroes don't do it all, instead the deploy their signature abilities in each and every battle. This is something the Vacian Spellcasting System is technically incapable of, for you are intended to use you're highest level spells and those are limited to such it tends to be a struggle to do exactly that even at four encounters a day.
Using the Blue Mage as your base you have full access to spells and many creature abilities without having to resort to Polymorph effects which may be an undesirable flavor addition. Like say you seen Shigekuni Yamamoto from Bleach and thought, hey what if I wanted to be fire focused. Obviously, only Desert Wind and a full spellcaster are the only capable classes since half-caster classes effectivly miss out on Orb of Fire or even the less deadly but still conceptually useful Fire Shield or Wall of Fire. You may even like the Dry Lich's Greater Drought and wish for some means to obtain it. The Blue Mage class, if allowed, gives you a set of near balanced rules for doing this.
As mentioned several times. It's in what you know that makes or breaks this class. Whether you want the Blue Magic aspect of mimicing or using this as a chassis to replicate your favorite character in literature/TV. Discuss with your DM what you want to learn and who you want to be rather than looking at this class and wondering if you can merge Quicken, Swiftblade's Haste, and Planar Shepard abilities onto a single character. Because honestly, a smart player can do it with Cannon Material anyway so why are you looking at houserules?