technically, there are many ways of producing "books" from xowiki pages. have you seen the examples screen shots in:
https://openacs.org/forums/message-view?message%5fid=544971 ?
in any way, you need a way to define a page order and maybe additional filtering criteria. in my opinion "spidering n levels deep" does not make much sense. there are no "primary categories". I am not very happy about the categories of the openacs.org/xowiki, since orthogonal concepts are pushed into a single category tree, where one needs a polydimensional categorization. for example, for each package, there could be code statistics and requirements, documentation of the package, future plans, etc. For example, "kind of documentation" and "package" are orthogonal concepts. There should be certainly some requirements engineering for the categorizations...
The pure liberal wiki-approach is great for building a knowlege base, producing good documentation requires more governance. ... have to rush...