What Are Some Similarities Between Buddhism And Roman Catholics?

I think you would find that doctrinally and in practice there are very few similarities

I know of a couple that I thought were interesting. Both Catholicism and Buddhism have some form of stigmata, but I'm not sure what the Buddhist stigmata looks like. In Catholicism it usually occurs as the 5 wounds of Jesus on the cross. Also, in both Buddhism & Catholicism there is a period experienced by many devout followers of each where they completely lose belief in their respective religions. Buddhists call it the Great Doubt and Catholics call it the Dark Night of the Soul, even though in some cases it can last many years. It's viewed as a spiritual test of their devotion to their beliefs, in that they have to overcome this doubt and disbelief to return to their relationship with God.