Let me mention that I like the rules for unwrapping.  I am sure it was not an
easy compromise, but I think it is an elegant solution to the problems you
point out with prior approaches, and will make macros significantly less
painful to write.

Just a couple of uncertainties:

   - Just to confirm: (car (syntax (1 2))) --> an error.

   - Could one write

       (define-syntax or
         (lambda (x)
           (syntax-case x ()
             [(_) #f]
             ...

     instead of (syntax #f)?  The definition of syntax objects
     seems to allow it.

   - Related, is (quote (1 2 3)) a valid output of a transformer,
     as opposed to (syntax (1 2 3)).  Again, the spec appears to
     allow it.

Regards
Andre