OK great, I was about to reply that the gcode looks fine and was confused why it would shoot up to max height (then I saw your edit).
So if you want, you can now properly set your Z height and run the gcode and actually perform the cut.
My normal workflow is essentially what we just did:
Home all axes using the limit switches
Use cncjs to jog to my start position and do a G92 X0 Y0
Probe Z via a macro in cncjs
Run the gcode