In my opinion, Proxmox is worth it for two reasons:

1. Easy high-availability setup and control

2. Proxmox Backup Server

Those two are what drove me to switch from KVM, and I don’t regret it at all. PBS truly is a fantastic piece of software.

As long as there’s a simple way to determine which containers use outdated images, I’m good

Yeah you can either have it update the containers itself, or just print out their names. With a custom plugin you can make it output the names of any containers that have available updates in whatever format you like. This discussion on the github page goes through some example scripts you can use to serve the list of containers with available updates over a REST API to be pulled into any other system you like (eg: Homepage dashboard).

https://github.com/mag37/dockcheck/discussions/146

I use node_exporter (for machines/VMs) and cAdvisor (for Docker containers) + VictoriaMetrics + AlertManager/Grafana for resource usage tracking, visualization, and alerts.

For updates, I use a combination of dockcheck.sh and OliveTin with some custom wrappers to dynamically build a page with a button for every stack that includes a container with an update. Clicking the button applies the update and cycles the container. Once the container is updated, its button disappears from the page. So just loading the page will tell you how many and which containers have available updates and you can update them whenever you like from anywhere, including your phone/tablet, with one button click. I also have apt updates for VMs and hosts integrated onto this page, so I can update the host machines as well in the same way.

OPNSense is a great option for turning x86 hardware into a router. That said, I would not recommend combining your router with other functionality. The router should be a dedicated system that only does one thing. Leave your NAS and web services on another machine.