Selfhosted

I'm in the process of migrating my system to some new hardware. I was curious on everyone's thoughts about Proxmox vs. TrueNAS Scale.

Here is some background - I'm currently running a mini-computer, with Debian, attached to an external hard drive. I host Plex, -arr suite, PhotoPrism/Photo backup space, Syncthing and some other apps. It runs fine, but could probably use some more memory. I also haven't had a lot of luck backing up all my family's data (on and off different cloud services) in one place in a way that avoids duplicates. My 4TB HDD is at about 80% full now. I have an offsite synology that I back up to using Syncthing. Syncthing has been having some problems lately, so I'm looking at some other options for that too.

I've been wanting to move my storage to an internal HDD, so I bought a larger used computer and a hard drive so that I can clean my setup a bit. It has an i3 8100, 500GB M2, 256 SSD, 8TB HDD and 24GB ram. To experiment, I've been running Proxmox and set up a few VMs including TrueNAS.

Proxmox has been pretty amazing. I thought I would have a TrueNAS VM, my Debian-based Plex/-arr VM, and then another Debian vm where I could just test different software that I wanted to host. I haven't really experimented with the LXMs yet.

I started testing out TrueNAS and saw that it also offers virtualization. If so, I probably wouldn't need Proxmox for my purposes.

With all that, here are some questions -

1. What do you think about Proxmox vs. TrueNAS? Any reason to prefer one over the other?
2. What do you think about having a Debian VM to host my Plex and -arr suite? What are the pros and cons of that method vs. hosting the apps on my TrueNAS or Proxmox as containers? I think mainly it would just be portability and isolation.
3. Currently, my external HDD is formatted so you could also plug it into Windows and read the contents. If something happens to me, I would like my family to be able to easily access the data. I need to figure out a good way to ensure it is easily accessible to them.

Thanks in advance!

Edit for posterity: after this post, I tried TrueNas, but was annoyed because the HDD was constantly being accessed. I tried unRAID after that, but had a similar problem with HDD access noise. I tried several cache drive configurations , but I couldn't escape the constant 5-second access pattern. I finally went back to Proxmox and will cobbler together my own NAS setup. We'll see how it goes.