Ah, ok. I remembered they got it in Savage species, not sure if there listed as getting it in SRD off the top of my head, and I'm going to be soon so not much time to check I'm afraid.

And yes, make a note that it doesn't stack with Words of Creation. The idea is one or the other so that you have role play options, not one then the other for a Tim Allen more power approach.

And as for the spell casting, maybe just make it so it advances Bard spell casting then? Or just advances Spell casting in general? Couple with slightly higher requirements so that it comes out more like a PRC then a base class and it won't be too broken.