With respect to the .dat files you're quite right that these are generated/created automatically by BS.Player when you (e.g.) test your skin in "folder format" (i.e. like Base skin). (Maybe see
my 2005-post on this very subject.)
Once you're sure everything is according to your likings, you can put the files which your folder contains (not the folder as such!),
including the .dat files, in a zip file and then rename the extension .zip to .bsz