I would absolutely love to see level 7-10 playtests. But in those playtests especially, if you build the kineticist to not have access to both a touch blast and a full-AC blast, that's a design choice, and you could have chosen otherwise. At level 5 (soon to be 6), Eram is guaranteed to only have one or the other, and he's doing great at 5 (and mathematically will only improve at 6, since he actually just lost a BAB at 5 without gaining a feel the burn and is at his relative weakest) even compared to the melee brawler.
If the Kineticist is balanced around having access to touch AC attacks, then each element should really have a blast option that's able to target touch AC. As it is, your hydrokineticist will be fine even if he decides to double-specialize in water, but a double geokineticist has no touch-AC option. Aether is a little better off since a double Aether has access to Force Blast, but punishing Earth specialists by balancing the class around an option that they alone don't get access to is a little arbitrary and uncomfortable.