There are different ways to look at 'open and free". Anything regarding nickel, the actual reader software, is not open and free. Anything regarding the FLOSS layer is open and free. Unlike many vendors who incorporate FLOSS, Kobo makes this layer easy to access and modify for people who have a knowledge of Unix systems. I can't speak on the openness and freeness of the actual hardware, however much of that hardware is exposed to developers the Linux kernel and Linux sources.

As for forced updates, they're really only forced if you go online or buy through the Kobo store on your computer. Turn off Wi-Fi and use Calibre, and you'll never see them. Registration is also easy to bypass, albeit you need to follow specific directions or have some technical know-how.