Excellent guide, Stefan. Though your posts are almost 3 years old, they are still useful to the community willing to start with automation.
By the way, I would also love to share my experience with Stellarmate OS purchased, copied on 32gb card, and running on RPi-4. I am super happy with it. And the hassle of managing cables and moving and connecting cables with laptop has become the past. Everything works on my remote laptop using VNC from my living room. I am also using SeTek Wifi Range Extender to connect to the RPi-4 and mount sitting about 30 feet far from laptop, and parted by many walls in between. In winter, and while using DSLR, number of cables does go up, but still could be managed well, in summer, and with dedicated astro cam, its a very neak and sleek setup. Here is the link to the pictures shot using this setup: telescopius.com/profile/pinakoza

Here are some pictures of my Stellarmate setup.