My wife sent me a fascinating link Noahide Halacha 101 or Meet the Adams Family which details a conversation with someone who tries to keep the ז' מצות בני נח. You can see from the conversation how complicated it is. Here is 1 excerpt:
“This problem went even further,” John continued. “Could we eat in a restaurant where forbidden meats may have contaminated their equipment?”
I admit that I had never thought of this question before. Must a gentile be concerned that a restaurant’s equipment absorbed eiver min hachai? Does a Noahide needs to “kasher” a treif restaurant before he can eat there? Oy, the difficulty of being a goy!
“How did you resolve this dilemma?” I timidly asked.
“Well, for a short time our family stopped eating out,” he replied. “You could say that we ate only treif at home. My wife found the situation intolerable – no MacDonald’s or Wendy’s? Although I know that observant Jews do not understand why this is such a serious predicament, but please bear in mind that we made a conscious decision not to become Jewish. One of our reasons was that we enjoy eating out wherever we can.
“So I decided to ask some rabbis I know, but even then the end of the road was not clearly in sight.”
“Why was that?”
“I had difficulty finding a rabbi who could answer the question. From what I understand, a rabbi’s ordination teaches him the basics necessary to answer questions that apply to kosher kitchens. But I don’t have a kosher house – we observe Adamite laws. As one rabbi told me, ‘I don’t know if Noahides need to be concerned about what was previously cooked in their pots.’”
What a fascinating question, does the din of טעם כעיקר apply to a גוי? This is just 1 example. These kinds of questions come up on every facet of life.