Where to mount NAS to sync all files types (not /media) & prevent total data backup?

Hello there

I got it right to mount my NAS with this tutorial. The shared file structure is mounted under /media, is showing up under the media section and it is surviving a restart.
I have two questions:

  1. I once read that with some directories the backup function will include all data. Sorry I tried to find the post but was not successfull. Will the mounted directory of the NAS be included in the HA backups? Which mount should I use to prevent this?
  2. Since I would like to use the NAS as storage for my Syncthing addon, I would like to mount it somewhere where all files (not just media files) are shown and copied. Currently Syncthing is only syncronizing media files. Where should I mount the share for for syncing all files? Is it possible to mount it not as media but (I would call it) data?

As always, any input is highly appreciated.