Oh, and I'd love to see a course on the sicilian hedgehog pawn structure (with white bishop on e2 or d3 rather than g2 like in the English)

2. Make connecton between video lessons and chess mentor courses:

I think that's a great idea - like a lecture followed by exercises. Maybe for some video lessons, the Chess Mentor courses already exist (for example - endings) => you could link to the Chess Mentor relevant sections in the video description.

Besides, it could help increase the # of Diamond users

How about How to Attack Sound Pawn Structures?

How to establish a game plan and modify it accorring to the opponent's move. 

Thanks Paul. Also, if you have not already done so be sure to check out the Chess Mentor course below as it relates to your suggestion.

http://www.chess.com/chessmentor/view_course.html?id=292

I have followed your sugested link and unfortunately the message is :"There are no more free demo lessons available"

Just wish that past offerings would remain for all, and fine with me if new demo offerings are dedicated to diamod or platinum levels.

But this Damocles sword approach is the least questionable.

Or perhaps I do not know how to get to the link properly.