Would Astro File Manager allow me to organize and display my books by genre, author, etc. since the Vox doesn't provide for this? Or is it mainly for apps?
No, you need reader software for that. Either Aldiko or FBReaderJ should do this. Aldiko is a bit more sophisticated looking and most people like it more; I prefer FBReaderJ. Either are easy to sideload. Aldiko downloads very nicely from Calibre, though if you set both readers to look in the same directories, you can use Aldiko to copy books and FBreader to read them. Aldiko is less happy if you use a usb cable to copy books over than FBreader is.