Not entirely. As we discussed several times before, the spellcasting speed increase was dropped (and if not, it should be) from the ability - it was replaced by spellcasting level increase, which makes the spells of that character to act at an increased level.Union, as proposed by TGM, didn?t make me happy, to be honest. Cleric mages don?t need MORE spells, and an increase in casting time speed creates too many problems, as we all know.
Also, the two kinds of magic are inherently different, have different restrictions and sources, so I don?t fully agree with the concept.
And I think it has merit to assume that having mastered both types of magic (divine and arcane) can have some beneficial effects on the character - though I'm open for new suggestions on it's exact nature. For example, there was an interesting suggestion: it would be nice if the high-level C/M could "swap" spell slots between arcane and divine spells - I mean, the Union ability would allow him/her to lose some clerical spell slots and receive a few extra for mage spells. Of course, this might not be implementable, but at least an idea, and truly fitting for this multiclass IMO. Something like this is what we should add here.
As you pointed out before, this is nothing more than an enlarged Remove Magic - and while it is nice, it won't truly fit this class. There some similar high-level spells in pnp (Nullification for example), but they are mostly pure mage or clerical spells.I propose an ability that would be truly unique, for this class: an Enhanced Dispel Magic, cast maybe at the equivalent of 20-25th level, with wide area effect and the additional bonus of NOT affecting party members. Maybe combined with a True Sight effect. This should open new strategical situations.
Also, I don't think we should turn a C/M into a spellcasting Inquisitor (your suggestion heavily resembles the combination of Keldorn's special innates).
Sorry, but again, this do not seems to be the best choice here - lower casting time has nothing to do with fighters, really (as someone already pointed out before my post) - if we would be talking about opcodes like "immunity to spell-disruption" for example it would be perfect. But since this is not the case..I?d move the casting time speed increase to an ability for Fighter/Clerics (?Combat Blessings? or a similar name): they can learn to effectively merge the two fields (combat and praying) and ?adapt the prayers? to a faster in-battle casting.