I do not speak from a position of *no* knowledge.
One of the things that happens in churches is the concept of visiting speakers. I'm sure you've heard of it; it is not a phenomenon isolated to churches. Some of my knowledge about what Catholics believe and how they behave and think are from such visiting speakers who are or have been Catholic and are there to teach, amongst other things, how other christian groups behave and what they believe. My exact example about Catholics who believe they are Christian whilst they believe that those around them in their own Catholic church are not, was directly from people who really believed this (much like there are Jews who also believe Jesus is the Messiah, but otherwise remain Judaistic Jews). Most other knowledge I have is from theological writers who identify themselves as Catholic, even to the point of having office in the Catholic church, and writers who have cause to discuss the image of the Catholic church in the wider society.
Now, as to who are "christians" and who are not... in my experience, for most people I have spent time with who identify as "christian", it is not a daily concern as to whether they consider attendees of a catholic or orthodox church as "christian" or not. I couldn't even say whether most would say 'yes' or 'no' on the question: most of the time, it simply doesn't come up. But most such people I have known would include Catholics as part of the Christian Church, just in a "more distant cousin" kind of way. I have seen this slight differentiation cause problems. Note this requires the distinction made between being "christian" in belief and being an attendee of a Christian Church. Most Protestants I know and have known through the years will make such a distinction, as do I (usually), regardless of what others may do.
OTOH, once the topic turns to church history, the Catholic church is always acknowledged as an irremovable part. In fact, "catholic" is nearly as old as "christian" and is applied by some to refer to all who call themselves "Christian". It is why the organisation based around the Pope is called the Roman Catholic Church so as to avoid ambiguity and perceived bias.
Surely I don't need to remind you that the history of the Christian Church(s) is a highly complex story with many points-of-view. I also have not mentioned at all desires to kill Jews, as this is a topic in church history I feel I do not know enough about to comment on.
I notice you have your discussion.
Wade.
