In theory an NAS should just be a private nostr relay, a bitcoin node, and a file storage syncing service with version history
Individual app backends should not be needed if we create the frontends to use Nostr and Bitcoin properly.
Discussion
Is it wise to have all on the same machine, from a security point of view?
Technically the file storage system is the only thing on that list that would have any sort of privacy/security concerns, as I think you probably keep the keys to both your nostr and your bitcoin stuff off the nodes and relays anyways
If you run a Bitcoin Lightning node it's a hot wallet, so keys are somewhere on the machine.