Hi Max
I can answer some of your questions...
New sounds/voices usually come with additional styles as you suggest.
The only way to input data is via floppy disc.
Don't mess about with operating systems and style conversion at this stage.
Always preserve you settings on a floppy disc before switching off.
There may be some forum members using the KN5000 for gigs - good machine - but most of us have moved on to the KN7000 with its much faster SD Card memory loading system.