After going through the structure of the code as well as the little documentation provided - I'm still left confused as to what is the goal of this entire project ?
To be the best damned Core Animation Layer-based graphics interface kit. Evarr. With two 'r's.
Regarding item 2, part of our goal with the Velvet framework was to support just this. We have a custom TwUI fork which allows two-way bridging between AppKit and Velvet, and Velvet and TwUI.