Hello Brian,
Of all of the things you mentioned, the absolute must for my family is an autograph book. For under $10, you have a journal of memories that your family can not only take home but bring back to Disney if you are lucky enough to return in the future! Some of my favorite vacation memories include my daughter posing with characters and asking them for their autographs. Then we pair up those photos next to their signatures when we arrive home. It's like bringing the magic home with us!
While we have not gotten into pin trading, my daughter loves Vinylmation. To each their own! Before we head to Disney World, we set a budget and make her aware of what her limit is. That way she can spend the money on souvenirs like Mouse ears or on her collectibles like Vinylmation. I know folks who love to trade pins while in the Parks. And I enjoy watching them barter their way for new pins. It's not just about the pins - it's an experience!
The same with the Passport available for purchase at Epcot. My friends bought the Passports for their sons during a recent visit and they proudly visited each pavilion in World Showcase. It really brought the countries to life. It was a lot of fun for my friends. But I know my daughter equally enjoys the
Kidcot Fun Stops.
So it truly comes down to what will work best for your family. I think no matter what you choose, it's bound to be a magical vacation!
Hope this helps!