Point 1:
With a closer look to the rshell readme I know how I could change the files.
Great. I should get used to work with vim, the default editor of my cygwin.
Nucleo and adding code to main.py
Re: Nucleo and adding code to main.py
You may want to install nano (I'm pretty sure that nano is available under cygwin) and learn that instead. nano is generally much easier to learn than vim. There are a variety of ways to tell rshell which editor to use.