I assume you have a measurement wrong, 700kwh during the night means (in a span of 12 hours) a continuous load of 58000 watts. If not, nice datacenter you got there!

I run multiple lxc’s hosting portainer, there I can manage all my docker containers in 1 web ui. Its amazing. You can share files with samba or cifs in unprivileged containers (issue 1). I use that for plex because it’s easier to use the igpu in a lxc then a vm. In portainer you can bind mount your docker volumes to existing folders in your lxc and then proceed to share them with samba/cifs/nfs (issue 2). Note that nfs mounting in unprivileged containers is not (easily) doable. Portainer fixes issue 3. I can’t help with issue 4 but aren’t nics already hardware bound?