Hello! That's awesome to hear about the characters! That does sound cool in regards to the child character experience. :)
The character's name does get displayed in dialogues, so a function for changing the name would be useful. I think all of the functions that you mentioned would make sense just as you described, so like "Set Movement Speed" and "Set Character Name" could be added to the the functions list. For those, you'd probably specify the entity ID of the character, and then the value to change the movement speed or name to. There will definitely be some sort of "Change Player" function, also.
Thank you for the feedback! I've been pretty busy this week with other obligations, but I am slowly wrapping up things on the camera scripting. I think the various Move Camera and Reset Camera functions are pretty much finalized. I hoped to get the Rotate Player and Rotate Camera functions included in the next release also, but I'll see where I am at once the weekend comes around.