the first thing you mention is the ipod doing a disk check. i don't know why it would be doing that when you plug it in to your machine, but you can manually start the process by holding back, forward, menu, and the circular button.
about the 5 second delay to play a song, this is normal if it happens to the first of a group of songs since the ipod is loading the songs into memory. it shouldn't be happening to subsequent songs already loaded into memory.
-r.