The Ben Ish Hai (Rav Yosef Haim of Baghdad, 1835-1909) writes in Parashat Tisaveh that haircutting is prohibited on Purim day, even if it falls out on Ereb Shabbat. The prohibition restricts the barber, not the one receiving the haircut. Therefore, technically, a Jew could have his hair cut by a non-Jewish barber. Nevertheless, that should be avoided, as there are opinions that bar receiving haircuts from a non-Jew all year, because, amongst other reasons, it may expose the Jew to certain impurities.
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The Halacha requires reading the Megila together with a large crowd, as opposed to having several smaller Minyanim. This amplifies the "Pirsum Hanes"-publicizing the miracle. The question is whether women, who are also obligated in this Misva, have the same requirement. Should they come join the large gathering at the Bet Haknesset or may they stay home and have someone come read for them?
Hacham Ovadia (Hazon Ovadia p.52) holds that they do not have to come to the Bet Knesset. He cites the Helkat Ya’akob (Rav Mordechai Ya’akob Breish, 1896-1976, Zurich), who explains that the famous principle of "Kol Kvudah Bat Melech Pnima"- (the dignity of the royal woman is inward) overrides the advantage of "B’rov Am Hadrat Melech"-(the glory of the King is amplified in public). Therefore, he rules that it is preferable for woman to hear Megila in the more modest environs of her home.
Nevertheless, there are proofs from the Poskim indicating that women should come to the Bet Knesset. For example, the Hagahot Ahshri (`Megila, Siman 3, cited by the Darkeh Moshe in Siman 690) writes that a person must come to the Bet Knesset for Megila reading: "Him, his WIFE and children." The Bach (Siman 687), Hayeh Adam and the Kaf HaHaim also explicitly state that women should come to the Bet Haknesset. This seems to be the accepted custom today, especially since women today come to the Bet Haknesset on Shabbat. Moreover, if women come to the crowded Shul on Rosh Hashanah to hear Shofar, in which they are not even obligated, it would seem that they can and should come to hear Megila, in which they are obligated.
SUMMARY
One should not take a haircut on Purim.
Women, like men, should come to the Bet Haknesset to hear Megila reading.