Although my daughter is only 3.5, I've begun to put thought into the prospect of her dating.
IMHO, I'd leave the open beer / alcohol out. I want the kid to know that it is me talking and in no way, shape, or form do I want him to associate the overt threat to him with me being impaired.
He'll know that there will be no excuse if something bad happens to my little girl.
Overprotective? You bet.