This isn't so much a question about viability but it sounds interesting for a concept character.
The ability is from the wishcrafter ifrit sorcerer archetype.
My confusion comes from the targets supplying the verbal components. Does this mean that the sorcerer 'pre casts' the somantic parts earlier in the day and later when the target wishes for it, then the spell is cast as a free action? And is it free for the caster as well?
The Ifrit still uses all the normal rules for casting the spell. So when the fighter wishes to be faster, the Ifrit still needs to cast their haste spell, taking a standard action to do so (or whatever the casting time is) and providing all the other components, but the fighter provides the verbal component as a free action.