Randy,
If I were to use a scheme such as that, why not just series or parallel ALL the switches? Then you use only one pin for the limits as the machine will fault out if any one of them activates? Not to be a smart butt, but the machine can only fault out in one direction at a time!
As Torsten points out though, a lot depends on the software that you plan on using.

Again, I use TurboCNC and it can be configured either way NO or NC. Personally, I yet have seen a need to home all axes simutaneously (sp?) [strike that, it don't look right:})] so lets say all axes at the same time. This is where I worked with the team at TCNC to get the program changed. I had previously written the necessary changes for V3.2x to allow single axis homing under G-code and it works great. I'm not sure, but believe the Machx series of controllers also allow you to set up the limits to suit yourself. Other programs, I have not used so cannot comment on them.

Bubba