Address switch
Having VME GA switch in parallel with backplane seems dangerous to me, if the switch is in the wrong position it could lead to a bus clash even though the user expects to be using geographic addressing.
More clever would be to auto-detect a VME64x crate using the backplane 3.3V to select between the switch or the backplane GA in the FPGA. This would though require 6 more pins...
Is the GA parity bit needed on the switch? Makes it painful to manually select an address as you always need to calculate the correct parity.
Relying on the internal FPGA pull-ups for SWITCH_N0 and SWITCH_N1 is not really optimal, I would have external ones.