Most stats per Arcane Swordsage with a mix of Bard.
IE d6 for HD, 6 skills from a mostly Bard list, 3/4 BAB, good will, sorcerer typed delayed spellcasting (max spell level = 1/2 class level).
The class uses the Arcane Swordsage's style of spellcasting with stance progression used for obtaining Special Abilities. I really like that mechanic and feel 3.5 was headed that way at the end of things with it's Warlocks, Dragonfire Adapts, Marital Adapts, Binders, Reserve feats and so on. There was just this press to find the right answer to break free of the vancian system that ultimately lead to the very metagame aspect that is 4E's power system.
So how to handle it? Well, if you look at the atypical Sorcerer they get 6 base spells and at 32 Cha 2 bonus spells up to 8th level. Almost 2 spell slots of every level for each of the four daily encounters. Now of course the BM gets free out of combat casting so it's a little unfair but that is what made my choice to use Charisma over Intelligence. It's possible to achieve a 70ish Cha score (see class boosters) which gives around six bonus 9th level spells, so as a comparison the Sorcerer knows more, probably isn't casting less, and if wanted could use more than 2 9th level spells in any given encounter.
Anyway, a couple of abuse limitations are thrown is such as no Adaptive Style or even Recovery resets which a normal ASS uses to turn their list of spells known into a list of ward & buffs they have on 24/7 no matter their duration. So unless you're caster level is 50+, you have no justification for walking around with any one short duration buff applied. Another hit is to the out of class progression seen in IL progression making you pay for multiclassing as normal. Then finally, forgetting a spell/ability ends the effect which fixes the original Blue Mage's problem of mimicking daily buffs without having to commit to knowing them. You simply can't look into Persisting a spell without committing it to your list of known spells.
The Special Ability adaption has limited duration and requiring an action to use goes back to the same reasoning in the spellcasting. You give an appearance of infinite uses, yet you can't have the ability continuously running. The DCs are intentionally high, 15+ and once per encounter, as something like Quickness isn't readily viable without favorable conditions even by level 7 (45% chance) when Polymorph comes online replicating that bonus. Don't get me wrong this ability can be used pretty abusively. Using creature abilities is one of the essences of a Blue Mage and nothing less than obtaining them works, but something like the Hellbreaker which already does this by ECL 14 is just far to weak to see real play. Even the Spellthief replicates abilities by level 8 but suffers from being too weak so this singular high potential ability simply isn't worth it's own weight if delayed or tied to a weak class.
So if I hit my mark right. This is a Tier 1 class, pretty versatile but a far cry from a a Wizard armed with Runestaffs and Dragons (thus any divine spell can be cast) or Cleric with Anyspell or any other known expanding trick. Its free from the vancian system yet not so much it turns everything into a continuous effect and a well optimized spellcaster should still dominate battles if they choose to. Certainly plays into a defensive gish concept but hopefully not too powerful.