Hi DaVu,
Sorry for my not clear message, it was already time to go to bed when I wrote it...
When I said OpenELEC I wanted to refer to LibreELEC.
I'll go with a RPi 3 then. Better to spend some more money than to spend hours trying to fix things.
So, to be more precise, about the remote control. For a Panasonic TV, although it has VIERA, I searched for CEC and didn't find the option to enable it. Thus my idea to have a separate cheap universal remote control do use with kodi in LibreELEC. Is there any guide on how to setup such a remote control for LibreELEC? Or is there any other solution that is better?