Lyrics, ties, extenders and hyphens

[Neil Killeen]

Hi

1) what is the correct thing to do with a lyric and a tie ?
   Should one use an extender like with a melisma ?  Thus

   a~ a
   Fish __

  Lilypond seems tolerant if I don't add the extender

  a~ a
  Fish


2) Also, I am finding extenders and hyphens get mixed up if I do   extend 
ties.

   E.g.

   a1~ | a1  | es1~ | es1
   Moun __ -- tains

  What I see after type setting is something like

    /--------------\             /-----------\
    o              o           o            o
               _         _                           <- First hyphen 
overlaps with extender
   Moun______           tains_____



3) Finally, on a matter of style of lyrics and punctuation. Is it good style 
to
   see punctuation (e.g. a full stop or comma) before an extender ?
   E.g.

   a~ a
   Fish. __

   If not, what should one do ?   Leave out the punctuation or try and
   poke it in after the extender somehow ?


cheers
Neil