General Storing of GuiXT scripts: To my understanding the GuiXT scripts are stored locally on each PC. How can we avoid users changing the scripts?

You can store the GuiXT scripts locally, and this is fine during development. But for the rollout to all users GuiXT offers much better options:

(1) Keep the scripts in the SAP database (SAP Web Repository or SAP Mime Repository)

(2) Use a file server in your LAN

(3) Use an http or ft server in intranet or internet

Please see the documentation "Installation for numerous users" for details.