Table's pctfree value

Please clear or confirm this sentences (Oracle7):

1. A VARCHAR2 datatype columns only allocates the needed space, while a CHAR datatype columns allocates the space for all the possible chars.
   (This MUST be right!)
   
2. A NUMBER datatype columns always allocates the space for all the possible digits.
3. A DATE datatype columns always allocates the space for a date,
   (7 bits).
   

If sentences 2 and 3 are right, then:

4) A table having only NUMBER and/or DATE as columns datatype

   is supposed to have pctfree=0, because no future updates will    require extra space.

By the way:

5) An index is supposed to always have pctfree=0, because his

   values (table's primary keys) will be never changed.

I suppose 2 and 3 (and 4) are wrongs...
Can you confirm?

______________________|    Stefano Unternaehrer    |__________________________
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