All the pneumatics rules seem to be satisfied. I'm definitely impressed, it is much more complex than any system I have ever built*. You might be able to cut down on time by using a servo actuated (relieving?) regulator in between the orange and blue parts of the system just after the solenoid. This would completely eliminate the need to have a bleed valve hooked up to a flow control which seems to be the bottleneck in efficiency. This would also conserve pressure since you are no longer bleeding away air. A good regulator and servo should be precise enough to be simple to program.
*Mostly because I have not had a chance to build
this, yet.