I think we can all agree that a CPU from 2007 which does not support VT-x is not a good pick even for something that is just meant for education.
ElevenNotes
No, 16GB RAM is not enough.
As I said in my initial comment, only MDM would prevent that, you can change the IP of the DNS server used via network settings on your phone, no need to download profiles.
Any reason why it needs a web interface? There are multiple solutions to work with applications from anywhere, probably the best and easiest is VDI.
Not here to help, just always baffled how people use their work devices for personal use.
I doubt that you can't change the DNS your device is using unless its a company device with company policies?
What is your real problem that you want to do that?
Why France? Do the few milliseconds latency matter that much?
Don't run docker as root, don't run containers as root, pretty simple to be honest.
You need to provide more information. You tell us you use Unraid and have a opnsense VM. You don't tell us what does not work (opnsense, npm, the service behind npm) neither do you tell us what you reverse proxy via NPM. Last but not least you don't provide any configs you use.
Tailscale.