Not all square tapers are the same. Shimano bottom bracket spindle/crank tapers use the JIS standard, not ISO. Campy cranks should ideally be mated with a BB that has ISO tapers. That's why they don't seem to fit.
I don't understand what you're talking about with the chainring bolts. The female half will fit through the bores in one direction but not the other? That makes no sense.