If Lava Lash somehow benefits from 7% bonus it would had to be a spell, and thus SHOULD benefit from Unleash Flame aswell, and it doesn't. That means it is ability - can be parry/dodged/blocked can not be resisted, also benefits from melee hit rating rather then spell hit rating. And lava lash doesn't benefits from 7% Flametognue Weapon enchant in cataclysm.