How are they supposed to know everybody's names? And say they do the name of the person in front of you, but not yours? Wouldn't that feel weird?

This is one of the reasons why I could never be part of a church that large. But Rev. S. communes everyone by name, and she usually gets any visitors' names before service or during Passing of the Peace, but if she doesn't, she'll ask right before she communes them. But I agree this would be impractical if you're communing thousands of people... but then like I said, I could never be part of a church anywhere near that size.