markers indicating a semitone & bowing markers....

[paul Malcolm]

I am a new user to Lilypond and Im a Viola player.
Typesetting music for string players is my interest. 

1)
What I would like to do is use a circumflex to mark a 
semitone. This is widely used by string teachers but I 
cannot see how to do it in Lilypond. For example e f  would
 be written (roughly)  e^f but it would be nicer 
than this where the little hat, or circumflex, is evenly over 
the two notes e and f. 
Is there a command in lilypond to do this ?

2)
i also found the upbow and downbow markers, but 
I could not find other bowing annotations, like where 
on the 
bow one should play, that is, middle heel point etc ...
Are there commands in lilypond for this ? 

3)
Finally there is another common marking used by 
string players to indicate holding a particular finger 
down while others are being played. 
This is typically a line underneath the stave that 
continues for the 
duration that the finger must be held down and is 
labelled with a number to indicate which finger
 is being 
held down. 
This is perhaps complicated but is there a 
means to do this in Lilypond ?

Paul