Thank you for your kind answer.

Complex numbers are like vectors. They have a real and a imaginary part. It's not so complicated if someone thinks about it that way.

Yes, that is also how I see them, but what confuses me is why they are limited to 2D... not seeing complex numbers generalized to more dimensions (3,4 ,5 etc...) implies to me that it is just a lucky convenience, not a valid representation...

And I still do not know why i^2 = -1... (of course, I understand it mathematically as well as how to use it, but not conceptually). It is at the heart of the whole complex number tool box, but it sounds so 'invented'... For me, this very thought contradicts why complex numbers are so effective in Physics. If they are so effective as tools to describe the physical world, there must be an element of physical or geometrical truth in i^2=-1. Any clue?

Lastly, I'm busy with my university and I already thought of making some videos, but there is so much uploaded to YouTube already that it isn't necessary I think..

You didn't understand my request. This would not be any video, like there are thousands (with many good ones) on Youtube. This would be to directly teach kids (via Skype or Dlive) by getting invested into the @OpenSchool initiative. But of course, your studies should take precedent.

Be well