Easy? That would be determined by your level of Screen Editor and Lua savy.
To do exactly what you ask -- disable all buttons except Ref All Home would require quite a bit of screen editor tweaking.
A simpler solution would be to modify the Enable button to check to see if axes are already referenced, and if not, ask user if they want to reference all axis.
If yes, enable machine and reference axes
If no, do not enable machine.