Advice about layout / page formatting

[Jim Duke]

I'm seeking advice on how to approach typesetting some hymns for use in 
worship.  The music in our worship is A Capella congregational singing, and we 
use both sheet music, which we put in folders in the pews, and slides, which we 
project on a large screen at the front of the auditorium.  For each hymn I want 
to produce a PDF of the sheet music, a set of PNG files for each of the slides, 
and a MIDI file to aid in teaching the hymns to the congregation.

The way I've laid out each hymn is to create the following files:

Slides.ly
Sheet-Music.ly
Words-And-Music.ly

Slides.ly and Sheet-Music.ly import Words-and-Music.ly.

The idea is to separate the music from the layout.  For the most part this is 
working well.  But before I get into some of the issues I'm encountering, is 
this a good approach?  I'm trying to make the Slides.ly and Sheet-Music.ly as 
generic as possible.  My end goal would be for the Slides.ly and Sheet-Music.ly 
to be identical across all hymns; but that currently isn't possible.  I still 
need to manually unroll the music for the slides (expand repeats, and music 
redirections such as DS al Coda, etc.).  If I could figure out an automatic way 
to do that it would be fantastic.

Sorry for the long context intro.  Now to my questions.  I'm having no problems 
at all with the sheet music other than the normal stuff new Lilypond users 
encounter.  But for the slides there are several formatting issues I'm having 
trouble with.

First, on the first slide of every verse I put a title at the top with the name 
of the song and the song number in our hymal.  On following slides from the 
same verse, there is no title.  But, I'd like the first system on every slide 
to start at the same place on the page.  As we present the slides the movement 
of the systems around on the page is distracting.  I'd like to fix them on the 
page if I could.  Because of how large I want the fonts to be, I typically can 
fit two systems on each page.  I have no idea how to accomplish that.  Is there 
a parameter that directly controls the distance from the top of the page to the 
first system?

Second, controlling line breaks has been a challenge.  Since I want to use a 
single source of words and music; forcing line breaks in the music doesn't 
work.  Is there a way to embed the line break instructions in the layout 
somehow?  I've seen references to using space notes.  For example, for Abide 
with Me (tune EVENTIDE), I might have:

For the sheet music:

s2 s4 s4 | s2 s2 | s4 s4 s4 s4 | s1 | s2 s4 s4 | s2 s2 | s4 s4 s4 s4 | s1 | 
\break

For the slides:

s2 s4 s4 | s2 s2 | s4 s4 s4 s4 | s1 | \break
s2 s4 s4 | s2 s2 | s4 s4 s4 s4 | s1 | \break

The Words-and-Music.ly file would have no layout guidance at all.  Would that 
work?  How would I combine the layout "rhythms" with the music?

That's it for now - this is already an abusively long email for a mailing list.