How to Selectively Collapse Member Expansion Headers on Cube Views?

Correct, row expansion is a global setting for the cube view, it is not possible to selectively start expanded a single member expansion, unless you use a non expandable selection, like list. It would be possible to parametrize rows with parameters in a dashboard and upon click expand them. Another alternative is to use linked cube views to handle the selective expansion of the selected row, in a second cube view that will pop up in a dialog.