sorry, but this would go way beyond the scope of the plugin.
the plugin expects you to not list things that are not available.
given that this is the case, there should also never be a need to edit an order once it has been received (though you could always add a note of some sort)
there is not (and probably never will be, though never say never ) any stock management as that would no doubt be the next request.
don’t get me wrong, I understand WHY you might want/need this but I’m afraid you will have to look elsewhere (like woocommerce for example) if you really do. I just do not have the capacity/time to implement this – not for quite a long time anyway
sorry