Well, well.
Switching the mediaserver to a Synology was at the same time much easier and much more complicated then I anticipated.
All the “mainstream” things, sharing data, providing the disk space for Plex, syncing Dropbox etc. went really easy.
Setting up a WORDPRESS site was also easy, but making it accessible via a domain showed me my limits.
On the other hand, the Synology is not that big.