Limit switch vs. home switch question

I'm working on changing my Bridgeport CN to a CNC machine. It
currently has roller actuater type microswitches as limits on the Z
axis only. Is it advisable to use seperate switches for limit and
home (or share the functions on a single switch).

What is the tradeoff between mechanical and proximity switches? Are
there other types I should consider and what would be their advantage?

Is there a safety advantage in using normally closed switches? (In
case of a switch malfunction, the BP will not run - rather than self
distructing)

Any ideas about how or where to put them on the X and Y axis of a
Bridgeport so they don't get damaged or get in the way would be
appreciated.

Thanks much for all your advice,

Jeff