In The Pockets of a Binder
It's kind of safe, though your autographs might get ruined because they're rubbing against each other and they might get bent if something is behind it. If you're going to store your autographs in a binder, put the binder in a very safe place.
Framed
Framed is very safe, nothing can ruin it and you can look at it constantly. Though, eventually you would run out of room on your wall since you'll have so many autographs!

Stacked One Above Another
I don't think it's that safe, many things could happen to it. Like I said in "In The Pockets of a Binder", the ink could rub against and that could ruin your pictures. Also, your autographs would probably stick together and then when you'd pulled them apart, that would rip the paper on the autograph below and your autographs would be ruined.
Just Lying Around
If you leave your autographs lying around, that's VERY unsafe. You could lose them, they could get wet, countless bad things could happen to them! I hope that everyone knows that....

Hope that helped everyone!
Many Thanks
Olivia