Wiring looks good. That's how I'd do it in series.
I'd go with Cat5 or Cat6 cable for limits & 20AWG or thicker for Estop.
Can't comment on the switches themselves.
Have you used shielded cable so far or not?
TBH on mine I didn't bother with limit switches in the end. I set up the soft limits in Mach3 in relation to home position instead with it stopping 3mm from either end. Seems to work just as well as long as I G28 home at the end of everything before turning off. Drawback is if it stalls/misses steps I have to mess about putting it back in the correct position to reset home again.