Thanks for the feedback @Caltoa.
Yes, we should probably have a small guide on Github as well. You will find the MySensors library under
/libraries/MySensors
The other sensor-libraries is just bundled for convenience. There are a lot of unexperienced Arduino users that wanted to get started building their own sensors and we have tried to lower the barrier a bit by providing working examples. Right now we do not automatically update any libraries (we need to verify examples first). And we have actually had to patch the RF24 library a bit to improve communication.
YouTube video is a good idea. I only wish I were good at video editing... ;)