X32 3 axis Rotary homing, limit switches and E Stop Questions

Homing and Limits are all controlled by Grbl Settings: Grbl v1.1 Configuration and Additional or extended settings

If you are running the 4-axes firmware included in CONTROL, checkout 4-axis CNC hot wire foam cutter for a more up-to-date version (currently in beta) that slaves the A-axis limit onto Z, allowing you to keep the Probe input (learn more about it Enable Hard Limits for A-axis with BlackBox X32 · Issue #67 · grblHAL/ESP32 and auto Square issue · Issue #64 · grblHAL/ESP32 )

Door input as E-Stop is not advisable - false sense of safety!

We don't recommend a software based Emergency stop / button connected to a controller thats dependent on controller/firmware/computer etc.

The software has an Abort (click button or ESC key on keyboard) for less-real emergencies, but a proper E-Stop should ALWAYS cut ALL power to the machine.

We recommend Wall Socket > https://www.rockler.com/safety-power-tool-switch > Power Strip> Everything else (Machine, Spindle, Dust extractor etc). In a real emergency you want to cut power to EVERYTHING at once. What if the dust extractor caught fire. Or the PSU is on fire. Or someone's hand is stuck under the router. That's why we advise against a software/controller based solution. When life, limb or property is at risk, cutting power is the safer option

 

It is. See

Set $44 (first homing sequence) to 4 (z axis = 4 in binary mask)
Set $45 (second sequence) to 1 (x is 1 in binary mask)

That would be your guy OdysseyCNCBrian - but AFTER he read those Grbl Wikis - they really are worth reading it has all the answers