Part of your problem can be solved using kiosk software, and configure the system so that default logon for the computer is to go into kiosk mode with a single sign on application like Chrome in kiosk mode.
Terminating the program, if they manage to do so, would send them back to the login screen which without proper knowledge of configuration and setup would send them right back to the kiosk software.
How to execute this solution could be found searching, but here are some links to get you started:
- Completely lock a computer and force it to use a single applicationCompletely lock a computer and force it to use a single application from SuperUser SE, which has additional links
- How to Easily Put a Windows PC into Kiosk Mode With Assigned Access from howtogeek.com with a solution for Win8.1
The principle is to create a dedicated user, and then when the computer boots or logs on to this user, a dedicated program is started. For Win7 this is usually accomplished using group policies (which also can alter what extra tools are available or not), or for Win8.1 using Assigned Access.