This is the only script available as far as I know and not being able to create better one I use it gratefully (thank you
itimpi)
I guess what you are suggesting (i.e. "... I would have calibre installed to the respective computers and simply portablize the config_dir and library folders...") is possible as well, but I like the idea of truly portable usb drive with all my books and calibre, that can be plugged into any linux machine and play while I am away from base.