How can I prevent the launcher for ubiquity in a persistent live stick

I have made a persistent Live stick for Ubuntustudio 20.04.2.0 LTS.

I want to let people boot from this stick to use it in the configuration I have made.

However I want to avoid that somebody playing around just clicks on the desktop icon "Ubuntu Studio 20.04.0 LTS installieren" and in the worst case does not understand the following dialogues. He might ruin the installed system on the hard disk or SSD.

Therefore I removed this starter from the desktop. However, although my stick has a partition casper-rw and it remembers things I have done in previous sessions (e.g. commands entered to a terminal, stored files and the like), the starter "Ubuntu Studio 20.04.0 LTS installieren" re-appears after each reboot, although I have deleted it before shutting down and the stick is persistent.

How can I prevent the reappearing of this particular starter.

One other question targeted at the use case of this persistent live stick to be tried by very computer-unexperienced people: How could I possibly prevent the (normal) user from any changes to /dev/sdaX, i.e. all partition of the builtin hard drive or builtin SSD? It must not be fail proof against people knowing about sudo, pkexec or the files governing the use of becoming root: Just the normal user should be prevented from altering the builtin disk. Would this be possible by mounting the partitions found on /dev/sda? Could one achieve this by manipulating systemd? If yes: how?

Solution 1:

quick and dirty method since you are using persistence, add this to your ~/.profile or add as a startup command in settings>session and startup>application autostart.

if [ -e "$HOME/Desktop/ubiquity.desktop" ]; then rm -r "$HOME/Desktop/ubiquity.desktop"; fi