Small bit about that Wi-Fi remark. Yes in your case it’s close to the server but Wi-Fi lets you mount the touchscreen anywhere. Wi-Fi completely makes sense here.
Absolutely. Try retrofitting this into a multi unit home and "just run a digital data cable up there". With some bad luck, this can easily cost as much as the whole unit.
I don't like getting everything on WiFi, too. OTOH I have ~30 devices on an VLAN isolated IoT WiFi network. This easily saved us a 4 digit expense and a lot of time(!) as opposed to installing new additional wire (redoing all the old ones was bad enough). Plus, I can do dumb stuff like control my office's window blinds individually, which is nice when only one of them has the sun blinding me while using the PC (temporary desk location due to ongoing renovations).
The equivalent energy monitoring device in my flat uses an RF link (no idea what kind, I haven't investigated further) to talk to its base station. Wireless seems fine, but WiFi itself seems like overkill.
