Mm.  So, the process is possible, but impractical.  And yeah, it sounds like it'd be best to stay away from doing that.  As to the Elemental Dragons...the term I have always heard for Terrestrial Exaltation is 'graced by the Dragons.'  That may just be colloquial, though.  Although, to be honest, if the Dragons aren't involved in some way, how do you get children whose Aspect is different from their parent(s)?  I dunno myself, I'm just throwing this out there.  And Transcendent Gaian Harmony seems alright, I suppose...though I've been told that some Charms from Dreams of the First Age are unbalanced.