Yes, pin 25 should suffice. I believe that is what I am using.
As a weekend warrior, I cannot speak to the proper or required cases for software E-stops vs. hardware E-stops in a commercial environment, but I’m sure someone else can chime in. I have an additional hardware E-stop separate from the software E-stop in case something REALLY goes wrong.
Releasing the E-stop resets the controller. You will lose all home and zeroes. The spindle will remain off.