It might work that you start two instances of VVVV one in 32bit and another in 64bit.
Do all the things you need with the Kinect2 in the 64bit instance and send those values via OSC to the 32bit instance.
In the 32bit instance render the things you need to do with Box2D.
As far as i know Box2D has never been ported to 64bit.
If you are able to use bullet lib then that’s now included. If you want to use box2d and kinect2 nodes as is then you might have to do as d0this said and use multiple instances. You can also send the transformations from box2d (or just needed part of them) to the 64 bit instance, just depends which one you want to work more in.
In general to be honest using multiple instances is a bit of a pain and can introduce more pitfalls, but is sometimes desired for optimizing (think multi threading). Or for Vvvvrankensteins…