Hi Matadem,

re:
> Is there a way for example to automatically cut 5mm at the beginning and the end of each line?

There isn't a built in way to do that but it can be done with a script. I've attached a script that will chop off 5 units from the start and end of all selected lines.

There are instructions on how to install a plug-in script here:
https://moi3d.com/faq#Q:_How_do_I_install_a_plug-in_script.3F

- Michael