Sweet, I guess it can coalesce independantly then
You heard the man!
True, although I seem to remember a proviso along the lines of 'unless otherwise stated' which may/may not be relevant....all published Skill Tricks are 1/ENCOUNTER, not 1/day
This implies that skill tricks are not the way to go for Thu'um, not that we should change what a skill trick is or how it works, just to crowbar a concept into an existant shell....in addition, you could take the idea that you can learn ANY NUMBER of shouts; there could be a note that says that Thu'um doesn't count towards maximum skill tricks.
Which puts it at loggerheads with the idea of Thu'um from Skyrim itself, since each power has a different cooldown duration, which progresses with the number of words used.Or have the ability to use Thu'um be a skill trick; you would have to learn words yourself, and then you could essentially Shout 1/encounter
I don't think skill tricks are a good fit, they certainly serve as a good reference point for power, utility and perhaps even cost, but they do not represent the mutability or scaling required for Thu'um itself.
We do seem to have a basic structure on mutual consensus, in that any character could learn to use this to some extent without too much investment (no multiclassing, self-crippling or shenanigans should be necessary), the 3rd word of each Thu'um should be restricted to only certain focused builds, and that there should be knowledge, feat, PrC and fluff support to make this a viable 'overlay' to the system.
The more I think about this, the more I'm reminded (possibly obscurely) by 'pneuma' from Weaveworld. I'm also repeatedly seeing an almost psionic edge to the whole idea of Thu'um, the 'power of voice and intent as one'. Not suggesting we make it psionic, but by looking at how psionics are like magic, but not magic, perhaps it could help us see how Thu'um would interact with existant powers and abilities?