Can not get my layout right

[Daniel Roussel]

Hi,

I'm a new lilypond user and I'm currently doing my first transcription.
I'm mostly done, the music, the lyrics, the rhythm staff and the fret diagrams
are pretty much to my liking.  

My problem now is with the vertical spacing.  I'd like to have more space under
the "Title" and "Instrument" and the score itself and I'd also like to reduce 
the large spacing between the music "lines"; the space between the rhythm staff 
and the next line fret diagrams.  Sorry if my wording is all wrong, I still 
have a lot to learn!

I put the pdf and source files in my dropbox to better illustrate my problems.

PDF (Annotated to explain what I'd like) : 
https://www.dropbox.com/s/zvh1t1odj6jm1px/Le%20Petit%20Bonheur%20Annotated.pdf

Source file : 
https://www.dropbox.com/s/c6o2hsmc3bi712v/Le%20Petit%20Bonheur.ly

Thanks a lot!

Daniel