Hood, I'm confused- if he removes pin 15 how will he trigger any limit stop?
IMHO, I think serial wiring w/ N.C. switches on the limit loop is the way to go.
Your idea of using a magnetic switch to save is clever but, I'm not really sure what it is getting you. You still have to mount and wire something at both ends of the table and ALSO mount a magnet to your trolley so, in my mind it seems like you have MORE to do with the magnetic system. I could be missing out on something here as I have never used these type of switches so, forgive me if I am not seeing something.
It sounds to me like your Home switches were working OK when we started- is that correct? If so, I would just leave that alone and be happy that you are getting your homing refs to work.
On the Limits loop... If you can change the receiver part of your magnetic switch to be N.C. I would do that and wire in series (wire from pin 15 to input on X limit switch-> output of X limit switch to input on Y limit switch -> output of Y L.S. to input on Z L.S. output of Z L.S. back to common). Wiring this way means that if any of those switches are triggered they will break that circuit and cause a limit stop.
After you get it wired, go to the Diags page in M3 and you can check if your switches are working by looking at the LEDS on the screen. They should light up when you trip your switches.
Good Luck!
Regards,
Sid