First off the ansewer you gave that Reform Lady does not really address the point and what would you ansewer the Modern Orthodox Feminists who do all the mitzvos you mentioned. It seems to me that you yourself do not really understand why a woman should not be counted in a Minyan. And if so I would highly recommend you find out the ansewer it’s not this forums place to discuss it however I assure you it’s quite relevent.
Also your feelings about what Hashem is more concerned about are really irrelevent, In fact Chazal warn us on numerous occasions not to try and decide which Mitzvos get more schar then others. In fact the reason why many say not to recite the aseres adibros each day is precisley because minim were stating the Aseres HadiBros are chalila “more” Torah then other mitzvos.
As for the crack about the fact that it did not happen in Eretz Yisroel that is patently Ludicrous first off a mitzva is a mitzva, second Purim is quite possibly a part of the mitzva of Mchiyas Amalek.
Thirdly this whole thing of making a chilul Hashem in the eyes of the goyim is quite perplexing Are we subjecting our understanding of the Torah to what is a Goy’s version of proper behavior?
As for what you state about making a chilul hashem in the eyes of the Goyim it is quitye possible a chilul Hashem in fromt of Yidden is worse.
And I would like to know which element of the forbidden is in the mitzva of drinking?