No worries, and it’s not a dumb question!

Not really, unless there are specific tracks you want. Most of the time it’s demos and singles, but imo they break the flow of a lot of albums. If there are no extra tracks then the only difference is in the physical packaging afaik (translation of the lyrics into Japanese, extras like postcards ame other collectibles etc.).

It’s because CDs were/are super expensive in Japan compared to the rest of the world and thee distributors wanted Japanese customers to purchase them at home rather than import.