Is foods expiration date exact date?
Not necessarily. But the company won't guarantee the product if used after the expiration date.
No, it is not an exact date. It is an estimate, biased toward safety, of when the food will be good to eat. Many of them last a long time longer, but the further past the date, the higher the chance is that it has gone bad and might make you sick.
The date on the broth is NOT an expiration date. There are only a very few foods with an expiration date. They are baby foods. The rest are "best by" or "use by" dates. The manufacturer is saying they "guarantee" maximum quality if consumed by that date. Nothing "magical" happens inside the package on the date on the outside.
Possibly, but it is not worth the risk. Cheese tends to develop mold after it reaches the expiration date, and the mold is not always easily visible. The manufacturers put the expiration dates on foods for the safety of consumers, so please, don't ever eat any food past the expiration date - it simply is not worth the risk. Food borne illnesses kill many people in the US every year.