Are there videos of the Stretch series showing people that are at a beginner stage?

Are there any videos showing how to do the movements in the Stretch series that show people that are not advanced in these movements?

All of the videos show 3 people doing the movements who are super flexible and there's no explanation given as to what people should do who have nowhere near that range of flexibility, so we just have to guess what is the best way to attempt some of these movements.

The great thing about the Foundation and Fundamentals are the "Technique Tip" videos which explain how to do the movement and often give tips on what to do for those that are struggling with some of them but there are no such videos for the Stretch series.

Is there somewhere that describes how to do all of the movements for the Stretch series for those of us that are beginners and still have little flexibility?

Yes, you can find  "Technique Tip. 

For example for the middle split and the new interface: 

Dashboard->"Lessons & Progressions"->stretch->"Stretch series - Middle Split"->"Stretch series - Middle Split"
Here you find the course splited up in the different  element with demo video and tech tip.

Fantastic, thank you Kjell. i didn't see that before.