lol, I'm on the same boat! I'm scared to delete them, even the ones that I have printed already just in case I decide I might use the same layout again for another page. Silly, I know, since most of them use templates anyway! But in my defence, I have to say that the pages I'm talking about are all from my boy's first year book, and since my dd only has a half finished First Year book in PAPER, it is my plan to make her a new digital version as well. So those layered files might still come handy for me.
I'd say: go through them again and see if there are any specific layouts you'd love to re-use. Keep those and delete the other ones!