He's young Nucky, doing whatever he could to get on, even if it mean doing some dark shyt.
Nucky wouldn't let him do it though, gave him cash and told him to do something legit with his life.
But we've already seen that through season 1 Jimmy and season 4 Will. We know that Nucky isn't willing to accept a gangster mentee to carry on his legacy and takeover like Torrio, Rothstein etc are. This wasn't some big reveal that Nucky would try and dissuade a young kid from pursuing a life of crime.
I'm not doubting that you are right, I'm just saying it's all a pretty pointless exercise. Better than him turning out to be Tommy, but still pretty useless.