1. The laws concerning bewailing, fasting and the performance of Shabbos labor on Purim, 8 Seifim: One may do work [which is forbidden on the Sabbath] on Purim, but places that have the custom not to should not, (And today, all places have the custom not to) (Kol Bo), and anyone who does [work] will never see blessing from that work, unless it is a joyful building, such as a house for a newly-married son, or an arbor for kings and officers. RAMA: And it is permitted to do work for a mitzva, such as writing Torah law decisions. And similarly it is permitted to do even work in the fullest sense for the needs of Purim (T"H Siman 112).
2. Even in a place that has the custom [to do work], this only applies on the day of the reading of the Megillah itself. But to forbid this for that is not our custom
3. The 14th and 15th are forbidden from eulogies and fasting for everyone in every place, whether for residents of a walled city who read on the 15th only or whether residents of cities who read on the 14th only. And the women, when they answer (the eulogies) all answer as one. And the kerchiefs, where they strike hand on hand. But not a professional mourner, where only one speaks and the others answer after her. They bury the dead without answering and without lamenting.
4. All of the elements of mourning we observe on Chanukah and Purim: RAMAH- never the less one goes to the synagogue to hear the megillah. If one can assemble a minyan in their home this is preferable. And there are those who say that no mourning (practices) are performed on Purim, not on the 14th or the 15th and this is the way to behave. Even the (public practices) of the first day of mourning are pushed off because of Purim but the private practices are still observed. And even though we don't (publically) observe mourning practices on Purim you can be counted for the minyan of 7 (for Torah Reading) like on Shabbat and thus ruled the Rav on his own.
אם חל פורים במוצאי שבת ואבל יושב בבית הכנסת בשבת במנחה לא יצא משם עד שיתפלל תפלת ערבי' וישמע קריאת מגילה ולמחרת לא יצא מפתח ביתו:
One says that a mourner is still obligated in sending gifts on Purim. (Rema: One should not send gifts to a mourner during their 12 months of mourning. If one though is in a city where the only person is a mourner one is obligated to send to the mourner to fulfill the obligation of sending gifts on Purim, unless the mourner declines the gift.)
יש מי שאומר שאונן מותר בבשר ויין דלא אתי עשה דיחיד דאבילות ודחי עשה דרבים דאורייתא דלשמוח בפורים דברי קבלה נינהו שהם כדברי תורה: הגה וכל שכן שחייב במקרא מגילה ותפלה וק"ש ונ"ל דדוקא בלילה אע"פ שמתו מוטל לפניו אבל ביום שרוצה לקברו קבורת מתו קודם כמו שנתבאר לעיל סימן תרפ"ז ס"ב ולכן קורא ומתפלל אחר כך דלא עדיף מי"ט ושבת כמו שנתבאר לעיל סימן ע"א כנ"ל:
It is permitted to get married on Purim. Rama: This refers to both the fourteenth and the fifteenth of the month, and one can certainly perform Pidyon Haben too. As to the custom of wearing 'faces' on Purim, and men who wear women's dresses and women wearing men's attire - this is not forbidden, for they have no intention other than pure pleasure. So too the practice of wearing kilayim, rabinically forbidden mixtures of clothes. And although some say it is forbidden, we follow the first opinion. So too, the custom of stealing from each other in a happy way - this does not fall under the prohibition of 'Do not steal', and this is what is done, as long as one does not transgress what is considered acceptable by the elders of the town.