Hippocratic aoth, Your friend is in agony for no reason. I have travelled couple of times in B1/B2 visa and never came across those questions. You can travel right after your visa is issued. The only thing you need to travel is a valid visa. It really doesn't matter when your training starts if you have a valid visa with you while you are travelling. Regarding entry at Chicago, there should not be any problem either. In case they ask, he can just say "I am gonna spend couple of days at Michigan with my relatives before heading south for the training."