By seudah sh’lishis of this Shabbos, there is no conflict similar to that if Motzei Shabbos is Rosh Chodesh–no matter what you eat, or when, it’s retzei, not al hanissim.
It is not easy to maintain a balance between traditional Simchas Purim and between seriousness in davening and kedushas Beis HaKenesses.
Costumes during davening is an issue—I would say that the common minhag is to yes allow and/or tolerate it, as this is “Purim garb.“
Similarly, there should be a certain tolerance for the ru’ach hayom— but of course only within limits, not stepping over the line.
But we should also be careful not to go to an opposite extreme:e.g., there are Shuls that do not “klop Haman” (except for the first and last),which is in direct contradiction to the Rama’s exhortation NOT to cancel or even mock any minhag Yisrael (and Rama is speaking specifically about this one! )for they were instituted with a cheshbon (690:17).