Currently the plugin does not have images associated with light on/off. That is something I can add very easily though. I am a little busy right now, but should be able to get to it within a day or two.
My configuration does not have much lighting, so I was not able to test out all the different lighting commands and status. Let me know if you run into any problems.
On your question about key presses, the API with the elk involves sending the whole password at once. In order to implement what you are asking for would be a little difficult. I think it would be easier, especially for me, if you were to try and use xlobby variables.