those examples are indeed broken. thanks for the pointer, i fixed them for upcoming builds. in the meantime you can just add an AspectRatio (Transformation) node to the patch and connect it to the Renderer. see the AspectRatio's helppatch for how to connect it.
regarding collision: you can always detect that manually of course by just comparing coordinates, right? whether or not to use box2d for that depends a bit on your actual usecase..
also recommended: have a look at:
which has a multitouch drag example in vl, where computing simple collisions would probably be simpler than in vvvv.