Cannot Home While Shared Home Switch is Closed

I get the error "Cannot Home While Shared Axis is Closed"

Are you sure that is the exact error message? If I remember correctly it is something like
'Cannot home while shared home switch is closed j=2'
Where 'j=<number>' will indicate the joint that was homing at the time. So this information will be very helpful in finding the cause.

Just a though, but probably will need to add home offset to all joints so it moves off of the switch when homing. 2-3mm should be enough.

You can use the 'halshow' tool to watch pin values:

linuxcnc.org/docs/devel/html/hal/halshow.html

Alternatively you could just try to invert the home signals by changing this line in your hal:

to this:

The logic sense is determined by the wiring and the switch/sensor and can easily be changed in hal, as mentioned above.
Your problem is that there is no change of state when the switches are activated and since the switches seem to indicate that they are working it's most likely a problem with the wiring.
Could you provide more information on the switches used and how you wired them to the board?

[edit]

What board are you using to interface the signals to the pc?