A. Like I said - unless you invented magical communication channel that will give latency and speed and and reliability of local NVMe drive to your remote NAS, no, remote storage can't replace local storage in full.

NAS is mostly good for backups, torrenting linux isos and serving them with Plex or Jellyfin. You are not installing software on your NAS instead of your machine. Or doing video editing. Or playing demanding games. I have file server at home and I still have ~8 TB of storage in my desktop, of which at leat 3 TB I can't move out.

B. If I have 1 TB of my work files, my wife has 1 TB of her work files, that's 2 TB of total storage. If both us need LLM, it doesn't mean we need twice the LLM as one of us.