Hello there, Iplvlsl. I would love to lend a hand in polishing the script for your video on the state of flow. Let me first tell you a little bit about me: I'm a professional writer and ghostwriter from the U.K., with almost five years' freelancing experience.
Having watched your video, I think there are three principle things I'd focus on doing. First, altering anything that sounds a little awkward (I realize English isn't your first language, and it's much better than my Russian!, so I'm not criticizing), I just feel that I can help the script sound a little more natural. For instance, the section 'advices' I would probably call 'tips'.
The second thing would be to work on creating shorter, snappier sentences - given you have the text on screen, I think the more concise those passages can be, the better. Of course, you mentioned altering the graphics, so I don't know whether you intend to have a lot of text on screen in the newer version.
And finally, because you've requested an injection of humor, I would slip in a few light comments. I have an idea of where I'd like to put those, but would need to give it some more thought in order to come up with exactly what I'd write.
Anyway, please feel free to check out my profile and reviews for more about me. If you're interested in working with me, I'd be very happy to hear from you. Thanks very much for your time.