Well... not trying to offend anybody... the word America (or American for that matter to refer to people from the United States. A part from the fact that it is highly offensive for the rest of the people that were born in the same continent it is highly inaccurate. It would be the same mistake as saying "Asians" to refer solely to people from Japan, or "Europeans" referring solely to French. The United States of America ("of" means part not entirety) is only one of the 3 united states in the continent. Mexico is "United States of Mexico and Brazil is "United States of Brazil". The name America comes from an Spaniard named "Amérco Vespucio" who wanted the continent to be one united territory.

'Alot' makes me sad. Different to is common in British English. I don't care whether it's different to or from, but different than kills me. =D

'There is' used when 'there are' would be grammatically correct. This is very common. Also, I was taught that 'different from' is correct, but many people say 'different to'.