@fets So far, I have only built the 5x5 board (but the others should be schematically identical). The only issue I have found so far is that I cannot get the ISP port to work. But I have checked and I have an identical setup on the 1.0 board and that worked, so I suspect the programmer is too weak to drive the net on this one. So it is not a board-issue per se, and might only be an issue on the 5x5 board as routing is the most complex on that one due to the size.
Welcome to the club!
Regarding radio's: The RFM69's with a C in the type have a smaller form factor (which is pin compatible with the predecessor RFM12B). The the 'W' and "HW' versions are larger in size and have more programmable pins (which MySensors does not use) but have exactly the same functionality within MyS.
All the footprints on the boards available in OpenHardware.io are for the 'W' and 'HW' versions so I'd go with one of these.
The 'W' uses way less power than the 'HW' which would be good the for the battery life of your nodes. Sensors powered by the grid can be 'HW', but usually, in the house a 'W' delivers enough TX power to get the message across. It might be a good idea to make your gateway with a 'HW'.
Hope this gets you a bit further. Good luck and show us your results!
I have published all the documentation in a Github repository. If someone wants to make PCBs, I recommend that you wait a little longer until you receive my PCBs and try them.
A couple of things, you put the device to sleep so while it's asleep, it won't respond to the commands to change the relays. Since you are combining relays and sensors, you need to keep the unit awake and find a different way to send the sensor data occasionally. For the relay status, read the comments in the sketch. You are saving the relay state and then reading that on startup. You can eliminate all of that code and just set the relay to off in the setup section.