I just posted a link to some posts by forum member Ghosty (who came to Catholicism “by way of Judaism”) in another post, #14 here. The topic of my post was the comparison of the Seder and the Last Supper (a Seder meal) and the usage of unleavened bread and its symbolism in Judaism and western Catholicism. The thread it is posted in refers to a Jewish feast compared to the institution of Peter’s papacy.
I’ve re-read the preceeding a number of times and don’t know if you will make heads or tails of it. The point is that the thread I linked to has interesting posts at #1 and #14.
I believe the church heirarchy, vestments, feast and fast days, etc also reflect our Jewish roots. For instance, the 1st century Jews fasted on Monday and Thursday. Catholicism kept the custom, but changed the days to Wednesday (the day Judas betrayed Jesus) and Friday (the day Jesus died on the Cross) to distinguish themselves. The role of priest being distinct from the laity, and only the priest being able to do priestly duties at the altar, are also Jewish in origin.