If a story swimlane is selected the user wants to add sub-tasks very often. To support that it would be a great improvment if a shortcut like "+" would be available to open the "create sub-task" window instead of pressing "t" and select the menu button "create sub-task" from the story menu on the right hand side.

It would also sufficient if a "create subtask" button would be available in the swimlane itself.