Hello. I just recently bought Zorin OS Pro and been looking for a way to rebind CRTL + ALT + DEL so it would launch Htop. As a power and windows user, I'm used to launch windows task manager via this shortcut and I do think many Zorin OS power-users would find it helfpul to launch a similar application in this manner as well.
Htop is not launched as a GUI application, but is a CLI command launched in terminal.
Zorin OS comes with gnome-system-monitor
Have you tested if it suits your needs?
Ctrl+ Alt+ Delete is usually an embedded command to look at shut-down, logout, reboot options so you would have to look at changing the command for that - is it really that essential?