I did custom autograph pages for the characters and my two DD's had a blast getting them signed. They also got a ton of attention from the characters who LOVED the one of a kind pages. But we saw characters that spent extra time with lots of kids for different reasons. I never felt slighted when a character spent time extra time with any child. Kids who wore costumes always got extra time. Kids that were in wheelchairs got extra time. Kids that were twins got extra time. Crying kids often got lots and lots of time. So what? I saw parents taking WAY more time to figure out how to use their cameras than it takes to sign a page. Just relax, the characters know the drill and can sign a book in about three seconds. Just be courteous and have the page and pen ready for signing.
I also agree with the OP who went to character meals to get autographs. We did that as well. More time to enjoy the parks!! That said, we would not do it again unless the kids asked because once was enough for us.
As for trading pins, I got some amazing deals on Ebay. I just bought a grab bag of them and the kids were thrilled. They loved the trading and could have cared less about which pins they gave away, so I was glad I did not spend a lot of money.
Finally, I made the passport books from the Dis Board and that was the one thing I could have skipped. My girls still love their autograph books and pins but could care less about the passport. I, however, loved having it for the scrapbook.
Have fun, whatever you decide!