First of all I have been a Photoshop user since 1999. I am a designer and an instructor. I have a course which has over 35.000 subscribers at Udemy. Nowadays I am a lecturer at Istanbul Kultur University and teaching Photoshop in Turkey.
Photoshop is getting easier and easier to use. I also teach Photoshop to my 8 years old son. He likes it so much. I think that, If you can redesign some features just for kids, they can become interested in Photoshop at a very early age. Maybe you can release another version of Photoshop just for kids or you can offer an alternative view (kids view) in the standard Photoshop.
Photoshop can be learned in primary schools and even in preschools. I think this is a necessity.
If you want me to share the features which I care about according to my experience, I can do it in a short time.