I switched to openHABian from an individual openHAB setup for my Raspi and I think this was the best choice. As I want to use additional packages, what is the best way to start some additional (e.g. motion etc.) software? which startup script to use and where to place? Thank you for your support
Any additional service you want to install on an openHABian configured machine that isn’t supported by openhabian-config need to be installed in the standard way. In other words, follow the instructions on motion’s website to install motion.
There is nothing special about openHABian in this regard. It is just a bunch of clever scripts that automates the configuration of standard Raspbian. In the end, if you can do it on Raspbian you can do it on openHABian.