You only need the stuff in the -bin zip, the other is source code and probably of little use to you.
Have you tried just adding a single song manually (not importing a playlist) and playing that?
Make sure you start SPS first then use the "Start Audiosurf" button. This is the most reliable way to 'connect' the two applications.
Make sure Audiosurf isn't set up to start in fullscreen (this sometimes breaks things, I'm not sure why).
If you're still having crashes, try verifying the Audiosurf files through Steam.
I'm not supporting SPS any more, so if this is a software bug it won't be fixed (although it is open source so anyone wanting to take it over can contact me about that).