Wow, that's a very professional document! And it looks like quite a useful library.
Have you considered making the API more "Arduino-like"? That is, wrapping up the functions inside of a class with a pre-instantiated instance (VirtualWire) that people can call methods on? And giving the methods names that are more consistent with those in the other libraries (e.g. begin(), read(), write(), available())? That might make it easier to use for Arduino people.