Yeah they're rather silly, but in a culture of "i'll sue anyone's ass" the corporations have to protect themselves. McShittyburger have "CAUTION:HOT" on their coffee cups because someone sued them for getting burnt by the "hot" drink. (the clue's in the title stupid!).
The nuts thing is due to a UK piece of legislation that came in about 10-15 years ago due to people with nut allergies eating something that had a nut trace and blew up like a balloon and exploded, so stupid govt dicks decided, ALL food items must contain warning! Even nuts! It's just all completely NUTS!