They wanted to make sure the people understood that they were trying to help Americans and it was an introduction for the constitution because it gave an idea what they were trying to say... hope this helps
The Treasury takes care of the money for all of the U.S there the ones who print out the money.
It was common for people to run for public office in order to get rich.
An addition or change to the constitution is known as an amendment. They have to go through many stages of deliberation before becoming part of the constitution.
Hope this helps and have a nice day! :)