I'm having some of the same issues. I've reinstalled the newest version of shape bender. I have a straight line on the red axis, but it won't let me click on it. I've had the plugin work yesterday for me, so I am not sure what the issue is here.
Here is the error that the Ruby console threw when I double clicked on the straight line:
Error: #<NoMethodError: undefined method all_connected' for nil:NilClass> C:/Users/charles/AppData/Roaming/SketchUp/SketchUp 2015/SketchUp/Plugins/clf_shape_bender/clf_shape_bender_data.rb:255:in
line_picker'
C:/Users/charles/AppData/Roaming/SketchUp/SketchUp 2015/SketchUp/Plugins/clf_shape_bender/clf_shape_bender_data.rb:187:in `onLButtonUp'