Alternate time frame - events do not unfold as they did/do for us now. This will be explained in later books.
Chapters are written from a first person point of view, but you are not told who that person is. You figure it out from their interactions.
You will not always know who is com (communicating, generic, as verbal is not the only way to communicate). Do you remember everyone who said everything in your life? No, just that something was said and it was important enough to remember and write down.
In later books a symbol other than (") will be used when someone is com in a different language or form (non-Hu). Italics means using telepathy.
Hint: just go with the flow and don't sweat the details.