Firstly, apologies for the resurrection (who knew threads had HQ/Shamanic abilities???), but in talking about the GaGoG, I was linked to here...
So - what's to stop an Elmali from getting the Sunspear spell if the gods are actually the same?
They could be going to the Yelmalian temple (out of curiosity?? To replenish RPs), having a chat with the local priest who tries to convert them, and being told of the awesome powers that Yelmalio/Elmal has, and you should have a try...
I'd see this situation of not having the spell more as "I didn't know I could get it" rather than "It's absolutely not available". If we take the getting of Rune Spells to be a mini-HQ, then all it should take would be to know of it, and then performing it. The Elmali could then return home and tell everyone that - yes, the gods are still different, but somehow we've forgotten that he still has that power (ie, Sunspear). I'd presume that the gifts/geases are a similar deal... we didn't know we could get them! The lack of Fireblade and Ignite in Yelmalio's cult is purely cultural (or could be argued as 'aspects').
Similarly, I can't see why an Orlanth Adventurous can't get the same spells as Orlanth Thunderous...if the god is actually the same.... (I can live with "isn't usually available, because we don't know those myths").
My perspective on this whole debate is fairly pragmatic... if Elmal was killed or trapped, would Yelmalians (and others involved in this argument) also lose all their powers? What happened to the other Air deities when Orlanth was 'killed' by the Lunars?
Lastly, when will someone realise that Monrogh was Lied to by a Trickster?