multi-tempi

[Hans Roels]

I don't really know Lilypond well (I just had a quick look at the documentation)
but I have some music notation problems and maybe somebody could tell me if
Lilypond is the right tool to solve my problems.

1. Is it possible to create a score with a fixed number of seconds (not bars)
per system? 

2. Is it possible to create a score with different parts/voices that each have a
different tempo? for example a score with a first part in tempo 56 bpm, a second
in 64 bpm and a third in 92 bpm?

3. Would it be possible to create a kind of script/template/score in Lilypond
that imports midi files (or some other file format) and creates a multi-tempo
score after the user has assigned midifile1 to part 1, midifile2 to part
2adjust,... 

I hope someone has some advice!
Hans Roels