If you are looking for a “dumb” TV, check out models that are for “digital signage” like the Samsung BEC-H series. They are as dumb as you can get while still buying new.

Unless someone has physical access to the ports/switch that the traffic flows through, they would not be able to see anything besides broadcast/multicast traffic if they were just snooping with Wireshark. The internal switch of proxmox and any hardware switch you have will forward unicast traffic to the ports those Mac’s reside on, so without port mirrors setup, no one but you should be able to see that traffic.

Between 3 switches, 4 servers, and my desktop also using one of my UPS units, I average about 850w, with peaks up to 1.1kw when my desktop is running. Luckily, electricity where I live is only 13cents/kwh.