Had trouble with the wall of text.
I have a much larger leg length discrepancy then you (50mm) and most of it (35mm) in in the femur. Dealing with a discrepancy in the femur is more complicated than with the lower leg (a lift on the shoe or shim on the cleat deals with the latter just fine)
I'd like to help, but you are not being very clear about exactly what your range of motion issue is, and exactly how it is causing problems. For example, if the issue is that your knee does not bend deeply enough, I don't get how clipless if going to help.
I will say two things to consider if the issue is your leg not being able to bend deeply enough:
1- Shims, or a lift in the shoe, by itself is going to make things worse because your leg will be more deeply bent at the top of the pedal stroke.
2- Shorter cranks will require less deep bending of your knees at the top of the pedal stroke.
3- Put the seat hieght were you need it for pedaling. Period. If the bars are too low, raise them.