I would use the customer service form and copy; paste your new started thread to it, letting napster explaining you the smallprint.

There exists an offline modus and you can burn cd´s, so I think each title you bought for 0,99 cent is yours. I don´t know anything about napster to go or the flatrates and who owns this titles, or even about an offline crack.

Maybe napster can help you more than fileforums can do because it´s a juristic question. According to what you said for them it should be no problem to help you. Subscribe to napster light which is free of charge.