Sure, he would refer to hormones when Lily is pregnant. At least the boys do when my female teachers are moody/pregnant... LOL
And yup, we use second and third degree burns That is exactly the same here as in America. I think it would be okay for James to use it yeah... I dont see why not.
Hope I helped!
EDIT: Ooh I claim Cumbrian! I tend to go for British though... I dislike London and being asociated with it.. I go for Scottish lol. I may as well be for all the notice London takes of Cumbria