One man is the first-generation American child of Irish immigrants, and Catholic. The other man's mother is a Romanian Jew who'd immigrated at some point vaguely around WWI, while his father is a Catholic whose family has been in America for generations. As you can imagine, this marriage was controversial for that time period, and that plays a part on the young man's life (in one story, he was always Jewish; in another story, he was Catholic for most of his life but became Jewish as a young adult). Both men are from New York, seeing themselves as Brooklyn boys first and foremost, and the bulk of the questions are related to the 1920's-1940's, but the story is partially/mostly set in the 21st century.
In case that last line didn't make it obvious, this is MCU fandom. The Catholic-Jewish man is Bucky Barnes, and the Irish-Catholic man is Steve Rogers.
Since there are walls of text behind the cut, my questions are about:
1.) Interfaith ritual participation
2.) Anti-Catholic vs Anti-Irish sentiments
4.) Dog tags
5.) Wedding traditions
6.) Language (Irish dialects)
8.) Living arrangements
I have done a lot of searches and attempted research on all of these. My questions here are for situations where I either couldn't find specific answers, I found conflicting information, or I'm unsure of where to start/how to look.
8 Questions, With Lots of Background and Commentary
1.) For the first story: The interfaith character, Bucky, went to Catholic school, was baptized, etc. BUT, his religious struggle started early in life. How much involvement in the local Jewish (and/or Romanian Jewish) community could he have despite his strong Catholic identification? How much could his whole family have, given the interfaith marriage? What are some traditions that might have been specific to Romanian Jews? Would it be feasible, despite being mostly Catholic, for him to have a Bar Mitzvah (especially if it was at his request)? And if so, would it be feasible for Steve to attend, despite him not being Jewish? (If it's possible for Bucky to have some Jewish community involvement despite being mostly Catholic, then they will all know Steve and probably spend the Bar Mitzvah trying to fatten him up. Again.)
1a.) In a variation/different story, Bucky didn't start out Catholic and convert later in life, but was Jewish from birth. Is there any traditions, rituals, or experiences he would have been barred from since his father is Catholic? What kind of problems would his family have faced? (Since I'm not putting Bucky and Steve in an orphanage, I'm trying to take a more lateral approach towards the "them against the world" angle of their childhoods most fics have.)
2.) In my understanding, while the 'Catholic' thing played a part in the Irish discrimination during the early 20th century, it was still mostly ethnicity/nationality. Does this mean it's possible that Bucky's father would look down on the Irish friend, despite the shared Catholicism? As an uptight military man and WWI/Great War veteran, he is going to dislike Steve as a 'pansy' artist who keeps getting his son into trouble; that said, a low opinion of the Irish would also be a good dimension to add to it for later story reasons. If so - or even if not - any ideas on how man like this would react to his wife being friends with Steve's mother, a woman who'd immigrated from Ireland? Would it be possible for them both to work as hospital nurses and have met through work? (Regardless of how they met, they will be friends - the amount of trouble Steve and Bucky get into, it's going to be hard for them not to.)
3.) When Bucky's parents die, would they be buried together, and if so, where? Would they have to be buried separately due to being of different religions? Would the fact that Bucky's father was a WWI vet have any bearing on this? (I can't even find a concrete answer for this dilemma right now, forget the Great Depression!)
4.) Bucky was baptized, and he went to Catholic school for all his life, meaning most of his documents and records would be of Catholic origin. However, when he ships out, as a "fuck you" to both his father (for personal reasons mostly unrelated to faith) and Hitler, he wants to put down his religious preference as Jewish. Would it just be up to him to list his religion, or would the army require some kind of proof of religion? Also, I remember reading that some Jewish soldiers would be issued extra dogtags saying 'P' instead of 'H' in case they were captured by Nazis. If this happened, would it be possible for Bucky to have a set saying 'C' instead? And for those more familiar with the fandom, when the Howling Commandos propaganda starts churning out, would Bucky being Jewish be a point of pride - i.e. a Jewish soldier going up against Hitler - or would it still be played down/ignored? Even if/especially if, despite being an adult, he is depicted as a "teen in tights" in more fictionalized propaganda? (Steve warned Bucky not to antagonize the USO spin-doctors. Bucky didn't listen.)
5.) What are some wedding traditions of Romanian-Jews and Irish-Catholics in America - in the 20th century, and today? What might have changed? What would a Jewish-Catholic wedding look like in the early 20th century, and what would one look like today? In other words, when these two men finally get married in the 21st century, what will the wedding look like? In the process of trying to combine Romanian-Jewish and Irish-Catholic traditions into one wedding, what traditions would be important for them to keep and what would they be willing to dismiss? Are there any important honeymoon or after-wedding traditions they will really insist on - and thus be in the middle of when their honeymoon is inevitably interrupted by terrorists?
5b.) Any notable deviations between Irish-Catholic and Mexican-Catholic traditions? What about Romanian-Jewish and Polish-Jewish wedding traditions? Mostly, if the two men look at these plans, what are some interesting differences they might notice? The two men's weddings gets adapted from the already-existing wedding plans made by
6.) As I understand it, there were a lot of dialects of Irish and little to no standardization, back then. What form of Irish would be the most feasible for Steve to learn? His parents came to Ireland as young adults right after WWI, but I don't really have any plans on which part of Ireland they came from, beyond the fact they came from a city/urban environment (mostly as part of a throwaway joke about nth-generation-city-boy!Captain America getting thwarted by a cow, so if that's unrealistic, I can scrap that). For an in-story reason, I need him to have grown up bilingual, or even having learned Irish first and then learned English a little later in life/secondary to Irish as his primary language. What dialect or kind of Irish would he have originally learned? (In the 21st century, he'll brush up on his Irish, and in the process learn more generic/standardized Irish of today).
7.) Google tells me that around this era, there were Catholic schools that accepted/provided for poor students, and Catholic schools for those who paid tuition for their students. However, were these ever the same schools/did Catholic schools take "scholarship" students along with students whose families paid for them to attend? (In other words, would it be feasible for the Irish-Catholic student, whose family is very impoverished, to be attending the same school as the "American"-Catholic student, whose family is well-off, if Steve were there because he is extremely intelligence/has some other kind of merit for a scholarship?) And for the story in which Bucky man was Jewish his whole life: is it more feasible that he would've attended a Jewish school in close proximity to a Catholic school that Steve attended, or that both of them attended public school?
8.) Would it have caused any strife among neighbors, a landlord, or any one else who can cause them problems if Steve ever moved in with Bucky's family (Bucky, his three sisters, and their mother) as an adult? I don't have any concrete plans for where they live, beyond "an apartment in Brooklyn", as I want the Barnes family to have been well off, but not necessarily that well off. Mrs. Barnes loves Steve dearly and considers him like a second son, to the extent that Steve lists her as his Next-of-Kin after Bucky himself, so within the family no one has a problem with him. Bucky's father is dead, and Steve's parents are both dead, so he moves in with the Barnes to help them out. (Or at least, that's what Bucky tells him to convince the stubborn punk to move in with them.)
Sorry for the walls of text. Thank you all for your help! :)