Only very few printers use max endstops. If you're short on pins this would be the first one I'd remove.
One enable pin for all axes is fine, too. Your printer is either off or moving on all axes. Actually, I'd use that pin to control the PS_ON pin of the PSU if you have one.
Another one is, using normally closed mechanical switches as endstops allows to chain them in series, so you can catch all your endstops with a single pin. The firmware knows the movement direction, so it can easily figure which of the endstops is triggered. I guess this already works in Teacup if you define the same pin for all the endstop pins.
One enable pin for all axes is fine, too. Your printer is either off or moving on all axes. Actually, I'd use that pin to control the PS_ON pin of the PSU if you have one.
Another one is, using normally closed mechanical switches as endstops allows to chain them in series, so you can catch all your endstops with a single pin. The firmware knows the movement direction, so it can easily figure which of the endstops is triggered. I guess this already works in Teacup if you define the same pin for all the endstop pins.
