Molds are surprisingly fast growing organisms. Soft cheeses like American can grow mold almost upon contact with mold spores. It is important to keep American cheese (and other soft cheeses) wrapped and sealed tightly. If you find mold on American cheese, it is not the end of the world though. Food safety sites note that cutting off the mold, one inch around and below the mold should be sufficient to remove it. Always be careful when cutting away mold to not let the knife touch it to prevent cross contamination.
Not very long. If it smells bad, It probably isn't safe to eat. Better safe then sorry.
about a week
Untill it starts smellin bad.
food
If it's still sealed up, overnight is safe. If it's been opened, I would through it out after a few hours.
It will depend upon the temperature of the room it was left out in. Once the cheese has been warm for more than an hour to an hour and a half. I would be quite cautious of eating the cheese. You might smell it to see if it still smells safe to eat.
Not long
it depends on the humitity.
No.
2 hours
Refrigerated food can only go unrefrigerated for four hours.
for 2 hours
7 years