Wookey
Muppet is not a slur
It would depend on the nature of the diet.
Assuming there were no negative consequences for the welfare of the child, I think most people would expect the State to butt out.
Yep. You feed a kid a vegan diet of chips three times a day, that's abuse. Malnourishment of body is as abusive as malnourishment of the mind. Which is what organised religion is, in a nutshell.