I'm not sure, but I think if you set powerpress to be at the end of the post instead of using the [powerpress] tag, it "should" only show when the user clicks more.
That being said, It does depend on hour your theme handles such things. Your mileage may very.
As for the 1 click download. That is dependent on the users browser settings. In some cases when you click an MP3 link, it will open quicktime or Windows Media player. All the plugin is doing is giving a raw link to the media file. How it gets handled is up to the user's setup.
Hope that helps some.
-Mike