We have been recording both the birth and death years by putting them below the name. We have also placed the name on both centuries when there is an overlap. That helps us to easily see whose lives overlap, rather than flipping pages back and forth, or missing the connection.
I don’t think the page protectors make it too thick, but I don’t know how thick a binder it would require, as we don’t use that method. The nice thing is that you can add extra pages to a century, or put focal pages in where they fit. We will use focal pages to create timelines for WWII, life of Christ, etc
HTH,
Vanessa