Is the brew basket plastic? wondering how much hot water comes into contact with plastic. bpa free?

The only thing that isn't plastic is the filter basket, and the outside of the machine. Everything else that comes in contact with the heated water is plastic.

Does this coffee maker has a heating plate for the glass carafe

yes with adjustable timer up to 2 hours.

does this coffee machine have a small brew option, i.e. 4 cups?

People don't understand that the 1-4 option it Is not about dispensing 1- 4 cups, its function is to preheat the water at the start for smaller a amount of coffee, which isn't necessary when a larger amount of water is used, as it has a longer time to get hot.

Amazon's website lists the capacity at 64 oz. which would be 8 cups at 8oz. each. Is this true?

Deceptive advertising. I measured the carafe and it only hold 45 ounces. I expect 64 ounces when it says 8 cups. Have never been fooled like this before.