I agree with Rob that you might as well just write out all the
defvars.
Another slight advantage of doing that is that in your IDE, the
"find the definition of this variable" command can position
you are exactly the right place.
One of costs of using macros
is that the IDE generally does not understand them.
Another coding-style principle about macros: it's
harder for a user to learn how to use a macro
than how to use a function, because the user
must learn a syntax. So it's usually not worth
writing a macro unless you get a proportionate
amount of benefit from it.
As an exercise in learning to write macros, of course,
it's just fine.