NFHS rules questions

[BuggBob]

I work other sports, but as you all know when your friends know you’re an official you get all the question. I'll admit I have a few myself.

NFHS rules:
1) Face mask penalty, I thought that all facemask penalties were 15yards, is that true?
2) Pass interference is pass interference regardless if catchable or not?
3) Intentional grounding, QB is being chased just before he is sacked he throws a long pass out of bounds that does not cross the LOS, does cross the LOS but crosses it Out of bound.

Thanks for indulging a curious mind.