These are not new problems.. Go rent the movie "Lords of Dogtown" (based on a true story) and you'll see that skate punk kids are really no different today than they were *30 years ago.* There are more middle-aged ex-skater punks out there than most people care to acknowledge.
To be honest, I can sort of identify with a lot of these punks.. Not that I was ever a skater per se, but I was a very angry young man not so long ago.. They hang out and skate and drink and smoke weed and 'prowl' (you know what I mean) TOGETHER for the same reason that gang members join gangs -- to feel like they're part of something.. Anything.. For a lot of them, it's all the 'family' they've got.
Honestly, you'd probably have better luck running them off by trying to GET them to skate at your church, than by trying to keep them from it.. If you act like you really want them around and want to become part of their family, they'll probably get weirded out and go somewhere else.