So going by this, that means that lifting a chair and moving it aroudn through an obstacle course would require the same roll. Lets say that 2 shift were strong enough to lifth the chair, then a discipline roll of 2 would allow you to have complete control over it and move it anywhere you want, no matter how complex?
It is just a personal issue harry has, that he can't manage to do it?
Actually, I'd say the rules do have something to say in this matter. I'd call that a Maneuver, for purpose of Evocation categories. Assuming it would take 2 shifts of power to lift a chair, yes, that's easy enough to control. However, the additional cost of 1 shift per extra exchange (or, for fluff's sake, let's call it direction change) WILL make this more awkward. If you move this chair through an obstacle course in just a single exchange, I'd argue that either the chair or the obstacl course are largely inappropriate for their intended use afterward... Maybe both, even.
Also, look at "Prolonging Spells" for how to make sure you have the spell going long enough to get it through said course. It IS stressful, and takes time, but it's quite feasible. The more complex the task, the more power you need to put into the spell, even if most of that power is only a constant trickle to keep the effect going...