There are definitely plenty of differences between the UK and the US. I am an American and like living here, but I've enjoyed visiting the UK. I like the dry, self-deprecating sense of humor, the fact that while people seem more formal, they are actually more caring, and of course certain cultural things. For example, some of my favorite authors are British, and so are many of my favorite rock bands.
Also, British Indian restaurant food is much better than the American version, and British pubs are great. However, the British idea of Mexican food leaves a lot to be desired!
Your comment on guns cracked me up. When my ex visited Germany for a business meeting, both the Germans and the British participants were quizzing him about guns, pickups, and so on, particularly since he and I lived in Texas. He emailed them a photo from a nearby gun store when he got home.
Re. church - I think there are more people involved in churches, at least in the rural areas of the UK. Many might be elderly people who grew up Church of England, but there are also young families who are going back for the children. There are also Hindus, Muslims, etc., who are involved with their temples and mosques.
Just my (more than) two cents worth!