Also, consider that the target is blasted in a straight line - in a relatively closed environment, it might not be possible to move the target more than a single zone.
What I also wanted is to allow the caster to be able to cast this type of Evocation on himself (without being too powerful).
Using it on a whole zone is interesting - it is not what I intended and I think that would make it too powerful.
I have also think that the Evocation is quite balanced if using it to push a target a short distance directly into a solid object (sure, this could easily be solved by using a straight Attack, but I wanted the Move Action to be able to handle this as well). Let's say that a wizard want to push a target only one zone away, into a solid concrete wall (which we for the sake of this example have a border value of 20 = way higher than what the wizard can handle). The wizard summons two shifts to move a man-sized target on zone. Then there is the solid wall, so the target can not be pushed further. The wizard then adds 6 shifts of power to try to go through the wall (but obviously fails). The effect of the spell would be that, regardless of the defense roll of the target, the target suffers 7 shifts of stress (1 for the zone movement, plus 6 for the attempt to go through the wall = stress equal to the border value, regardless if the border is crossed or not). Compare that with an Attack spell of power 8, which generates 8 shifts of stress, plus any additional stress based on how much the caster beats the defense value (which is stress that is not added in the case of the Evocation Move action). I think that it still feels OK, what do you think?