flash (macromedia): It's not obvious how this is done. Also, is there a way to remove points on a path- or add them? I assume there is, but again, not clear how it's done.

To manipulate the anchor points in a path, use the Subselection Tool (white
arrow in top right of the Toolbox) and it will become intuitively obvious. You
can select, drag, and delete anchor points, as well as move their handles and
change the curve of the path.

To add anchor points, use the pen tool (looks like a nib pen).

All of the above can be found in just about any beginning Flash tutorial,
including the tutorials that come with Flash. And your specific questions would
have been answered by spending approximately 30 seconds searching Flash's
built-in Help.