As you have discovered GE plugin does not support drawing or dragging without writing some code yourself.
There is an extension library that I have found useful for draggable placemarks. Use makeDraggable().
Example here: http://earth-api-utility-library.googlecode.com/svn/trunk/extensions/examples/draggable.html
Source here: https://code.google.com/p/earth-api-utility-library/source/browse/trunk/extensions/src/edit/dragging.js