Hi,
I haven't uploaded any video on the net yet. As for your motors, running them at lower voltage you will not get their full speed. Smaller differences are not important but here you've got ~4 times higher voltage.
Current is proportional to torque. Overloading the motor will lead to higher current but this will heat it more, and eventually damage it. It is suggested to keep within the specs.
Yes, I've tried to face a aluminum bar here, but the machine isn't rigid and stiff enough for a good finish. It was build for non metallic pieces mainly.
The force of the cut strongly depends on the sharpness of the tool. The newer the tool, the less force and much less noise generated while cutting. I've not measured it, nor I think I need to. My main restriction for fast heavy cuts is the spindle current limit for now. Since the regulator is also homemade, 10A was the setting I could sometimes bring it to the end. Anyway for a normal work it's enough.
Todor