1. I notice that my JP games (SF3 Third Strike and Capcom vs SNK 2) have bigger cases than my US games. You have to put them side by side to notice, but I think it is because of the door(?). The door on the JP games are bigger because the tabs that hold the booklet are higher in height than the ones on the US door.

It's impossible to explain just by text, you have to see it for yourself but unfortunately since I don't own any other JP games these are the only examples that I can give. If you try to put the booklet for SF3 or CvSNK2 into the door of a US game case, it won't fit, because the tabs are too low.

This is a real long shot here, but I was wondering if anyone knew where to possibly get a replacement door for the cases. Right now I think the only possible way is to just spend $5 on some cheap crappy JP game on eBay and use that case. :(

2. What exactly is a spine card? It's just a piece of paper that goes over the case? How does it stay in place? :)