I agree that I don't like the sync stored in a db rather than a directory of files. I just reminded myself that Remotely Save also saves to webdav on my Synology NAS and to Nextcloud. Since I have both available, I will be looking at them again.
I use Linux Mint on several NUC-style computers. I even use it for servers even though it is a Desktop. Based on Ubuntu but it does fewer stupid things. I run many docker containers. Run Plex in docker. Can't speak to the refresh rate in X. Wayland is coming, but it will be a while.
Contacts has a Trash can. Deleted contacts are deleted after 30 days. You can empty the Trash yourself. Log into the web interface and find Trash on the left.
Maybe add an Android device to one of the HDMI ports?