You’ll need to use | float(0) in templates. All state values and attributes start out as strings. Also setting a default value in the float(#) cast will ensure templates don’t break when the value is invalid.

That means use this style: {{ state\_attr("light.kitchen\_sink\_ceiling", "brightness") | float(0) }}

We need more information to recommend anything. Do you need high voltage switching? Do you have zigbee, zwave, or only wifi available? How much integration or local on device control do you actually want or need?

I’d have to check my iptables syntax again but I’m not sure you want the FORWARD between the networks unless C has a manual route to get traffic for the 192.168.15.0/24 network back via B. You just want to NAT A behind B’s IP on 192.168.38.0/24. I think the forwards are sending the traffic without doing NAT on A.

All that yes. The Wooting One (original that uses IR light) let you use buttons to simulate controller axes, change how hard you need to press to activate, and add second functions to keys. It was an interesting idea but I found the gaming part the original keyboard to be only usable in a limited set of games as it’s not as sensitive as a controller stick, and as a keyboard it wasn’t great either. Hopefully V1 problems, I know they had through another version of the IR keyboard, and then came out with the Hall effect keyboard. I like the idea but never could get used to it, and when the spacebar was loose I retired it after fixing it.