I’d be tempted to reduce the Might to 5, unless this is meant to be an elder elemental or something like that. Right now it’s more powerful than a black dragon and nearly as powerful as a red. That’s not necessarily bad, but only if that’s what you intend.
The Nature score can scale based on how big and powerful you want this thing to be. Again, 10 is good for a really potent elder elemental. If that’s not what you’re going for, a Nature of 6-8 makes sense.
For descriptors, I would really want a fire elemental to have something like Consuming. Maybe swap it out for Roaming since Roaming and Seeking Heat cover a lot of the same ground potentially?
For conflicts, can these things be summoned and/or banished? If so, it might make sense to include Banish/Abjure as one of the conflicts (and in that case I would definitely want a cleric with the Sanctuary of the Lord of Shields prayer to deal with this thing!)
Incandescence is cool. I would limit it to any characters that lead an action or help with an action during a round. That gives the group an option to try to protect a party member by not giving them an action or having them help. Also, you should spell out how Incandescence interacts with the Cloak of the Lord of Forges prayer. I would suggest that anyone protected by the prayer doesn’t take splash damage from Incandescence. The direct target would still take damage, as they’re taking the full brunt of magical fire.
As for the special, you mean nonflammable liquid like water, right? I imagine that inflammable liquids like oil – and other fuels like dry wood for that matter – could heal it.