the line
"deb http://debian.ch-ct.de/ jessie main" doesn´t work for me and i cant find a solution via google

This will reduce the need for live code changes and accelerate and simplify the work on holMOS

Using gettext, there should be at least a german version of all string in the glade and python files, so the user base is getting bigger.

Because the whole scripting-stuff can be pretty confusing especially for beginners, it would be very useful to have a Help/Documentation Browser to view the tutorials and references for matplotlib, numpy and cv2.

The overlay's size is fixed to 1920x1080p - is there a reason why that doesn't depend on the pi's display's resolution?

In the Scripting-Interface, the matplotlib.Figures are stored in an array inside the ScriptResultViewer. Before every result presentation, the tabs are cleared, but the figures are not closed.
This results in unneccessary memory consumption.

When opening a script, the contents of the script editor are replaced completely. It would be useful to have a small warning popping up when the user tries to open up a new script, although previous changes have not been saved.
This would also apply to the deletion of the main window.

Hence, the MainWindow class has to keep track of the changes made and saved, to avoid data loss.

It would be really helpful for users if the script editor provided auto completion for the given modules.
The GtkSourceView has support for that: https://developer.gnome.org/gtksourceview/stable/GtkSourceCompletion.html
example

It should be possible for users to share a whole project (meaning: the image+script+figures).
An export would be really cool, e.g. as html file, so the script and the results it produces can be viewed in a web browser too.