Re. unnecessary warnings. I once bought a packet of mixed nuts which said 'Warning, this product contains nuts'. Now that really was unnecessary!
One Autumn at the garden centre I bought some hyacinth bulbs to force for Christmas. The prominent label said:-
Warning! These must not be eaten!!
An even more prominent, handwritten bit of card had an arrow pointing to the warning and then said:-
Sorry about this. We know you are not that stupid, but the very stupid rules insist that we tell you not to eat them.
Brilliant.