The first video with Coach Kyril I'd grade as pretty marginal. Forearm (not wrist) pronation is correct, but you don't bend your elbow to get more wiping action. You do rotate your upper arm, but CK didn't say that.
Hit in front is good. Really bad is that he seems to be saying that you're forcing the forearm to pronate through just a brute force muscle contraction. The pronation, like the wrist flexion that provides the power, happens via stretch-shortening. The power comes from the core and legs and is stored in the forearm and wrist. The whipping action as all of this stored power is released is where the power comes from.
His "second phase" and the first drop feeds show the racquet pointing backward towards the back fence. But note when he starts to hit harder late in the video the racquet is pointing more to the side during his prep phase, which I think is much better. He also uses stretch-shortening, power from the core, blah, blah, when he's hitting harder.
Will's video is better and brings up some very good points, but still misses some others. His WW forehand still has a lot of classic elements, like the neutral stance and long, pointing-to-the-back backswing, that detract from some of the potential of the shot.
I really like the video that shows the difference between a classic fh and a modern fh:http://www.youtube.com/watch?v=G0uCQBiH2Ko
Here's a good teaching video on a modern fh: http://www.youtube.com/watch?v=G0uCQBiH2Ko
and here's a good example of the best implementing it: http://www.youtube.com/watch?v=kmhvKafCYsk