Hi Aleks,
Love this idea, but with so many boxes, within one video, of you doing different things, I can tell you that that is going to be too busy for a kid, especially when it comes to storytime. Kids like storytime, because it's relaxing and they can fantasizes about the places in the story. All those windows of you doing different things will take away from both the relaxation and their ability to focus on the story and fantasize about it.
Also, what age group of kids are you targeting? If really young kids, then it is their parents that you need to hook in and quite frankly they enjoy reading to their kids. Kids that are beginning to explore youtube on their own, would generally be at least 8 years old, so might need some more mature reads then your current stories.
Looking forward to seeing where you take this.