I would mention both and let them decide how important it is.
First, the employee eating a competitor's food in the dining room. This is important for two reasons. First, any one, customer or employee, eating food brought in from the outside exposes place to a lawsuit and health department problems if that food causes food poisoning. Second, a person visibly identifiable as an employee eating a competitor's food in the dining room tells customers the restaurant's food is not desirable. I certainly would not want that occurring in my restaurant.
As for the take home peanuts, this may or may not be acceptable behavior. Having been to this restaurant, I have not seen that behavior. Mention it and let them decide how important it is. They might reward the employee, tell them not to do it, or do something in the middle.
Some will say this MSP/client doesn't receive out-of-the box comments well, maybe even giving shoppers problems for doing it. I can't disagree with that observation. It makes me hesitate to suggest reporting it to this company. However, in general I know there are many companies and clients that would love to see these type of comments. It is these types of comments that really show the value of mystery shopping.
Happily shopping Rhode Island and nearby Massachusetts and Connecticut