Hello,
I am finding it very frustrating that add Swimlane column will only add a column on the end (right most); add Swimlane row only adds a row at the bottom.
When I want a column in the middle or on the left-side, my only choice is to add a column on the right and move everything across.
If you want people to use yEd as a designing tool, I think you need to provide flexibility with inserts.