I think this teenager need to figure out what he wants to do with his life. It's clear that he's still trying to figure out what he's interested in while in college (change of major). Thus, it makes me wonder just how much passion/enthusiasm he actually has with respect to pursuing a VERY expensive training path to a career he probably has little exposure to. Where did this "interest" come from? Was it because he spoke to Uncle Rick and it sparked an idea without any depth of knowledge as to what he's in for with an aviation career? Or is this interest stemming from an "always wanted to be an airline pilot since I was 5"? Given today's aviation career environment, I would not recommend this career to anyone. Hell, one of my first questions to new students is if they are looking to get into an aviation career with the airlines. If their answer is "yes" I sit them down for about an hour explaining to them just how big of a horror show it is to get involved with it. 50% of the time, the light goes on in their heads, and they do it for fun instead. The other 50% walk, which is not a bad thing.
Your nephew has time to get a degree, and see what's available to him in the real world. Who knows, maybe another year in college will focus him down into something he really wants to do. There are a lot of trades that produce a ton of cash and is quite a respectable career path that also provide opportunities for off the books jobs. Veering him towards an airline career is no better than asking him to take all his money and put it on the craps table. Roll the dice. You might win, but then again, you might lose it all. There are better odds in this life than an airline career.