Well, with multiple users you’d need to decide what the use case is for the whole NAS and then work down from there.
Are you sharing everything in the NAS with everyone? In that case your NAS setup is fine, just a little permissive, because with RW to everything, the end users can break everything.
If it were me setting this up, I’d have different mount points for different users. 1 mount for each user that only they can read/write (not even you should be able to see it), and 1 mount that everyone can read/write, maybe if you want to go a little bonkers, 1 mount that everyone can read, but only you can write to.
Then you’d mount those three to separate mounts in your /media, and you can link them from your home directory for specific use cases.
Obviously this is completely overkill, but you can take the parts that sound appealing to you and ignore the rest.