I'm curious, did you watch the video I provided?
Yes. It has been posted by anti-religious and/or anti-Christian advocates on at least a half dozen sites that I check in on occasionally--or it has been posted by Christians as an illustration of anti-Christian bias. It provides interesting theories for why things are as they are but no more proof than do U.S. customs that are similar to other national customs prove that one copied from the other. I also write about and teach this stuff including the reason for and the origins of many Christian legends, customs, rites, and rituals or, more succinctly, how Christian thought has developed.
The core of the argument is that the legends, myths, rites, rituals, customs, symbols, etc. are extraneous to and sometimes purely human inventions to Christianity in its pure and unfettered form. Sort of compare it to some of the rites and rituals and language that you see/here in a court of law or in the House or Senate in Congress. These often have nothing at all to do with the legal or legislative process, but they are custom and just seem right when they are done. The legal and/or legislative process could still be accomplished without them as Christianity would still be Christianity without all those customs and symbols that some seems so anxious to use to discredit Christianity in its entirety.