Hi Duckfather,
I'll also be interested in responses to your question. Like you, I don't want to rely on the internet to be up in order to operate equipment. I'm also worried about the number of account details I have to give to Google so it can operate devices for me. Even worse, none of the companies seem to realize that in the real world we have families and they should not have to sign in with your account or be able to buy movies using your credit card!
For me the only current solution is to install and configure OpenHAB on a small computer such as a Raspberry Pi or Intel NUC. You can still install and use other hubs such as the Philips Hue at the same time. OpenHAB has drivers for most things and you can add Z-wave / ZigBee USB dongles to your hub to control them if you wish or talk to devices indirectly via Ethernet/WiFi to device specific hubs. If you want to take it to the extreme OpenHAB even has support for Jarvis to let you control everything with your own voice. It also has a web interface so you can create kiosk like controls and there are mobile apps too.
Whatever you do don't forget the 'Grandma rule'... if the Grandmother came to stay, could she operate the lights and set the thermostat without a mobile?
Of course the big downside of this is the necessary experience required to set it all up. But that's why I joined the forum!