[CW] Morse Code Questions

[Richard Slone]

Hi all,
  I have some Morse Code questions that have been puzzling me.

1.  Should there be a letter space or a word space, between the last letter
of a word and a punctuation mark?  Words are more readable to me if they
stand alone.  W1AW doesn't put a word space, only a letter space.  The Art
and Skill of Radio-Telegraphy book says to learn complete words by sound, so
it seems to me that having no work space before the punctuation changes the
sound of the word group.  Now I have to learn the word sound in variations
that include every punctuation mark.  Would I be labeled a bad operator if I
included a word space rather than a letter space before a punctuation mark?
2.  Is it inappropriate to use the apostrophe?  W1AW broadcasts skip over it
when sending contractions.  I know it is a rather long symbol, so should new
CW operators just forget about learning/using it?
3.  Where is the official internationally approved list of code symbols?  A
URL would be most helpful.  I have learned the symbols by sound, but if I
want to check for a new symbol (e.g. @) or to see if .---. is assigned a
meaning, where I do I look for the official answer?
4.  As near as I can tell .---. is not a recognized Morse character.  It is
shorter than some others.  Any ideas why it has never been used?
    Thanks & 73,
    Richard, KG4VOX