Eric, the phase angle should be set to 120 degrees.
Regarding the regenerative braking, I have mine set at 50% and it really helps you stop quicker when you need to brake hard, as well as reducing the wear on the brake blocks/pads. Mine is fitted on the rear and works very well as a sort of anti-lock brake when going down steep slippery surfaces.
I would suggest you give it a try first and see if you can adjust the regen level to suit your riding preference. If you then find that you really don't like it, you can set it to zero.
I'd like to see GM produce a variable regen system that would also work in combination with the cruise control to provide a constant dog walking speed on the flat, going up hills and going down hills too.
Alan