Some points from things I noticed reading through this thread:
* SMB is the protocol used to move Windows files through network transfers. For example, if I want to go to my NAS on my local network on Windows, I go to \\nas.homelab.local\share. On Linux, I got to smb://nas.homelab.local/share. It's just the protocol used to navigate to the destination, like https:// before a website URL. When you set up your data pool of all your drives, you create "shares" which are essentially folders for you to divide your content. On Linux, these are called "NFS" shares, but for compatibility, everyone just uses SMB shares.
* Plex cannot currently be installed through the HexOS panel, it can only be installed through the TrueNAS panel. The end result would be the same, though: a container would be created on top of HexOS/TrueNAS, and that container would run Plex. The only apps that can be installed through HexOS itself is Immich and Plex.
* Plex and Immich are currently the only things that could be installed on the HexOS
> Having my download/organize media content on another pc connected to the network, then moving the content over to my hexos machine?
I run all my services on Linux. What I do is I mount the drive the SMB share as a folder on my other containers and they access the files directly. I run everything on the same machine (more on this in a bit), so I get 37 Gbps between my services. No need to worry about moving files back and forth. I just work on them via the network.
Have you considered running HexOS as a VM on Proxmox, rather than installing it on baremetal? While it's not officially supported, the only issue I have seen in such a setup is that I cannot install apps through the HexOS panel, but I can do so perfectly fine in the TrueNAS panel. There's a little more initial setup, but it's mostly just passing through the drives that would actually have the data pool, in your case the five 12TB drives. The initial setup would be a bit more complex, but you would have a lot more freedom in how you want to run things, such as limiting how much CPU or RAM to give HexOS versus other services. You would also have everything run at the same priority. Proxmox would also allow you to run LXC containers, whereas TrueNAS can only run Docker containers. It also allows for full Windows 11 servers.
Like I said though, it's initially more complex. The hardest bit, for example, would likely be setting up the HDD and GPU passthrough. There's a lot of community scripts to help automatically install a bunch of services, but GPU and HDD passthrough is a manual task (at least for me it was) There's multiple threads talking about people's experiences with Proxmox if you do a search through the forum.
As for game servers, I would use some kind of tool to make it easier. Pterodactyl Panel is a TrueNAS application and supports a lot of games. I prefer running an Ubuntu Server container and using LinuxGSM for my game servers, since I prefer using the terminal.
For your Windows 11 services, Proxmox should also fully support running a Windows VM perfectly fine for whatever you need to do there.
