Buckling and moving roller (Karamba)

Hi guys,

First I wanna thank you for your time reading this question! Thanks. 

Second, I am not really sure about the buckling analysis. I am trying to analyse a simple simply supported beam, pinned from one side and roller from the other (Free to move on the x-axis) with applied load horizontally on the roller support. Yet I am having problems understanding the Buckling modes component in Karamba and also having hard time to understand what NModes is. 

Third, I applied horizontal force on the roller support yet I can't see it moving in space in Rhino. It's fixed there but the roller is seen to be fixed when viewing. How can I make it move to the left with the load until it snaps (according to bending strength of the material assigned)? 

Please find the GH definition bellow.

Thanks in advance.