Let's see. Providing alcohol to minors? If they had a sip of beer that'll stick. Corrupting morals of a minor? If they had a sip of beer and anything untoward happened(it's a frat party remember). Somebody smoked a joint, did a line, had a fight, porn on tv or made lascivious comments to the girls. That'll stick.
Kidnapping and false imprisonment? The girls have been reported missing and the parents don't know whether they are alive or dead for at least 3 days. Someone took them to a party 40 miles away without parents knowledge and wouldn't give them a ride home and they are minors. If they were a few years younger there would be no question.
Let's add another: felony threatening. Surrounding the father and putting him in fear of his safety and that of his daughters.
What's sick is this father being charged at all. You don't seem to have a problem with those bogus charges.
That little gem stood out in your post as a shining beacon of truth. Absolutely. If they were a few years younger, there would be a seroius problem. However, like it or not, legally at least, there is a world of difference between 13 and 17, or even 15 and 17.