I agree with everything that has been said.
If you do intend on chasing cables in, my advice would be to just tack it all in place and use it for a few months, even years, and then chase the cables in when you next decorate. It really is best to get the system work properly and exactly how you want it before spending time and money physically integrating everything into your home.
You might decide to use a Z-wave light for example as well, which sometimes requires a deeper back box, so you could sort that out at the same time i.e. bury the back box, fill, sand etc, and then decorate later.
Living with unfinished walls and cables tacked visibly to the wall may not be ideal, but it makes more sense than putting everything in in one go only to find something doesn't work, or at the other end of the spectrum, having loose cables trailing about the place. Then once you have lived with the system, and are happy, chase it all in and decorate.