I like the idea of commentating on vids, but I think the execution needs work. All of the issues (length, execution, etc) can be solved by planning. You don't need to script everything you say, but you should approach it like any presentation you would give, plan out you main points and structure so that the end result flows nicely and doesn't go on for more 5~7 minutes.
It could also help if you got someone else to do it with you. People see things differently and notice things the other will not, especially for the non-Mu character. Again this should be someone in person so you can plan the vid.
Lastly, editing. I don't know much about E-live but when your doing a vid, edit the result. This doesn't have to be anything fancy, but you can do stuff like pause the video or just redo small parts that sound bad. (in the planning leave small pauses between points so you can cut and paste audio with ease).
This one is the best of those two, but to be honest I'm not a huge fan of either. But it's your video, and the content is infinitely more important than the music.