naa, it would be impossible to sell a product where you could only mount it on a horizontal plane. the motor shaft looks like it would hold it on, and when its running it floats on air, so that would not be a problem of orientation.
LOL YES IT WOULD BE A PROBLEM!
Gavity is everything!
well harddrives use an airbearing to allow the arm (head?) to float over the spinning platter at a ridiculously small distance, and I don't believe there is any active control to adjust downward force to correct for a change in orientation.
The air bearing upward force is balanced by a downward magnetic force. As long as these "springs" are very stiff relative to the weight of the impeller, it shouldn't be an issue.