Thanks for all the help guys. My Visualizer for SU16 is up and running now.
However, I had a minor issue which I thought I should share here. I couldn't see a 'SketchUp 2016' folder under 'Application Support' despite having SU16 installed and being used for a while. I even had Kerkythea plugin installed so that plugin data must have been in that folder which didn't exist I suppose?
What I did is; Install SU2015, install Visualiser, go to Macintosh HD/Library/Application Support/SketchUp 2015, duplicate 'SketchUp 2015' folder and rename as 'SketchUp 2016'. Didn't have much hope but voila! It's aliveeee! Waiting for my second render now.