I would recommend you to first double-check if it is not violating author rights to use the episode app only to make youtube videos from it - I am not a lawyer but as I remember the episode stuff can be used only inside the episode and if you will for purpose use it in other media I strongly doubt that Episode will tolerate it - especially if you would have channel successful enough to make money with it.
Episode portal and animations or backgrounds is not “free” stuff with which you can do whatever you want.
also when people say “own music” - they usually mean music from some existing authors - not music they did by themself - and such music is also protected by the author’s right.
So watch out that your "creative freedom’ is not just about using what is not yours without proper permission.