Actually, the entire basis of the OP is flawed.
“The kids that come from ages 13-18 tend to stray from the derech (not all but alot) and i think this has to do with the difference bet. american chariedim and israelin chareidim.”
How do you know? Did you take a survey? Did you actually talk to the kids and their parents? Do you have some expertise in this field? How do you know they weren’t “going off the derech” before they came?
Oh, how I wish I saw this thread when it started!