Simple, safe, effective limit switches?

Hi again my ever resourceful allies!

I've been having this terrible recurring nightmare where an encoder
fails and a servo wedges the table as hard as it can against the end
of the mill and the little controller that could keeps feeding more
power and the servo becomes an induction heater.. and... and... I
lose sleep over it at night..


So, let's talk about limit switches.


I have an idea of how I want to setup my limit switches, and I'm
about to buy the stuff for it, but I was wondering what feedback I
could get first, just in case I'm wrong (or things can be done
better).

What I was thinking of doing was serial-chaining a whole bunch of
microswitches in NC (so they pass current through them normally, but
break the circuit when they hit limits). This would mean, normally my
current would flow in the circuit, but as soon as any axis hit the
limit, or if I pushed the emergency stop button (also in series),
then the circuit would be broken. The chain would drive a big relay
(20A). The relay would sit on the servo driver side of the power-
supply capacitor, so that when the relay was off, there would be no
power for the geckos (not even the resisual in the capacitor, since
this would be disconnected from them). A second relay could activate
and this could be used to indicate to the computer that the driver
had faulted/E-stopped.

So, is this a good idea? Or will the geckos burn from suddenly having
motor back-EMF and no cap to discharge it to? Or will it not matter,
since, diconnected, the servo circuit would not be closed? What about
the cap, now stranded and connected only to the beefy PSU? Would it
steam and boil and fill my shins with aluminum electrolytic ionized
shrapnel?

or is this a workable idea?

Thanks!