a) Yes
b) Yes absolutely correct but the steering rack issue is relating to bump steer rather than fit. (the mazda front subframe is 727 and 654 respectively between mounts)
I have just got off the phone with Talon who already have prototype suspension mocked up, their setup uses a book build with regards to mounting points, his figures tie up with the ones you posted above so my build will have a fractionally narrower track - about 2" overall.