You can and you can't share the Switches for both jobs.???? . . . . . . You can if you don't put the switches thru the Relay. The relay is a problem for Homing because of delay which you don't want.

If you want the Limits to run thru a relay then you need separate set of switches for homes.

Now personaly I don't have problem with running Limits straight to inputs provided the input can accept 24V to lessen chances of noise. Lots of BOB's are 5V only so this why relay is used so can still run 24v thru the long path to switches but keep the 5v signal line short and lessen chances of false triggers etc.

If your BOB can take 24V then Mach will allow you to share switches to do both Jobs.
So if you want Home switches (which I suggest you do) and don't want to fit extra switches (which I suggest you do) then remove from going thru the relay. Just keep relay for emergency stop.

End of the day Limits are Not Emergency stop but rather positional loss and has such only need to stop the control or disable the drives. They don't need to kill power completely.

But for sake of couple of £££ then I'd fit Home switches. In fact if had to lose one or other then I'd have Home switches before Limits if as they are far more useful and you can use Soft limits if need be.!