Lightroom :: Making Musical Slideshow In V4

It would be nice to not have to create a string of songs in Garage band and then hope they transition nicely with your photos. Mostly, I just want  the whole show to end gracefully. Even if I fit to music, it just ends. There is no option to add additional end screens either which could br useful for the abruptness. My slide show is long so I have to listen to the whole thing every time I want to see if my adjustment worked for the end. There does not appear to be a preview to just check the end and how it is performing with the music.
 
The picture in picture aspect is so crisp and nice. If the music just worked as nicely.
 
So my questions are:

1) How to fade the music at the end

2) Is there a way to preview the result without listening to the whole thing?

3) Does the newere LR5 provide an option for selecting more songs and manipulating the fades?

4) Is it possible to add additional end screens?

5) What is different about LR5 from LR 4?