No, you don't need to use Sup.log! It was an example, to show how to do something concrete after getting a behavior (in this case, Sup.log displays a member variable's value in the browser's development tools, but you could be doing any number of things instead).
If you haven't already, looking at some of the demo projects might help: http://docs.sparklinlabs.com/en/resources/demo-pro... and https://bitbucket.org/sparklinlabs/profile/reposit...
Regarding collisions, there is a built-in axis-aligned bounding box collision system called ArcadePhysics2D. You can find a tutorial here: http://docs.sparklinlabs.com/en/tutorials/collisio...