if you are going to sell products from licensed materials, i would spend the money to have a paralegal or copyright attorney to provide you clear explanation of the law. it would be far cheaper to go this route than to end up fighting a case through the courts. to me it is all the costs of doing business.
after seeing what the music industry did to ordinary citizens, even college students, with downloading music and how they actively pursued them through the courts and won every time, if i planned to sell licensed goods online or at a show, i would spend the few dollars to get on the right side of the law.