Thanks!! That was a great explanation. Actually it validates the plan I was thinking about speeding up listening and speaking.
Indeed reading can be more easily tracked down in terms of progress. There’s enough graded material both for japanese learners and for japanese audiences to make a clear path to progressively increase the difficulty of the material.
As for listening, for me it’s much harder to grade the content I’m using.
Some shows I’ve watched so many times, used as sentence mining material, and overall make it to the point that I’m quite familiar with those so I can listen those same shows in my mp3 player like if they were my daily soundtrack.
I think I’ll give it a go to the Shadowing book, I have the first one, but never went through it. Same for these Listening Training course and Speaking / Pronunciation course… It was hard to practice listening and shadowing when there was such a clear progress in reading skils, and the path was quite straightforward. Now I’m moving to Japan in about 4 months, so I think the benefits of actively practice this will be quite palpable this time 
So… I’ll try to work over my listening as much as possible, and leave the speaking for when in Japan.
Thanks again!