It is possible to open a Tableau support case by visiting the following link : https://www.tableau.com/support/case

By default, the shape that a Heap map uses is a "Square". See below:

To change a measure so that it automatically aggregates as an average instead of a sum, you should right-click the field in the Data pane and select Default Properties. In the Default Properties menu, you can set the default aggregation for the measure, such as setting it to calculate an average by default when added to a view.

Since Sales is a measure, it can easily be depicted via size.
To drill down and change the level of detail, Country is the correct choice since it will contain STATE. We can then depict the various states by different shapes such as circle, square etc.
Finally, the Profit can be depicted via a color! Eg - Red for poor and green for excellent profits!

By default, the shape that a Heap map uses is a "Square". See below: