I think the problem comes from the fact that you have to introduce the id and not the name in the importStyles method (check the code that is given with parseStyles)....we have used the name and not the id from the impotation because is the one shown in the Word interface.....although we recognise that the process is a little convoluted :-)
If you continue to have an error importing the styles...could you please send the corresponding Word file and script to contact?