OK.. so 'splain it to me Ricky..
I realize that Valani is a pretty obscure deity.. but why would the 'Fireshaker' not have the 'Fire' as one of his Domains? Seems a perfect target for the cleric 'Separatist' archetype. In some places he seems to be described as the lord of volcanoes.. in other places (Faiths of Purity) .. more like the sea god who watches over islanders.
Seems like an oversight to me.
Title aside, fire is nowhere in his portfolio to be fair. He is all primordial life, all powerful and ever changing nature, as generous as it is harsh .
The whole volcano thing is kinda the ideal example of that, more than it is the core of the faith.
If there was some volcano based subdomain I'd absolutely expect him to have it (although even then, maybe more through Earth) . The Fire domain, as it is, doesn't really fit Valani's concerns.
For that matter, Islands are as relevant to him as volcanoes - if not more - and he doesn't give Water either. He's just not that purely elemental.
I do agree that it makes sense for separatist sects to grab Fire though.