Cool deal, glad you have it working! I keep a backup of my roms, marquees, videos,etc., on my main computer, so if I have to reinstall Batocera, I can just SSH in and copy the files back to my arcade machine. I use a format like this: scp -r ./backups SorthiousArcade:/userdata/roms/
The -r option is for recursive, so you can copy whole folders over. The SorthiousArcade is just an alias I set up for my arcade machine’s IP Address, so I don’t have to type in an IP/password each time; just ssh SorthiousArcade. I also keep a text file in my BatoceraRelatedFiles folder, with the location of artwork, videos,etc., so I don’t have to look it up each time.
i.e. /media/SHARE/themes/es-theme-forever/CUSTOMIZE/videos/<system_name>-video.mp4
I found commercials for each of the game systems and now it plays them when you hover over a game system; atari 2600, colecovision, NES, Sega Genesis,etc.
Anyway, hope this gives you some ideas, or helps in some way! Good Luck!