Well, Hinoryu, this is mostly based on the anime, with the assumption that Orre and the personalities found there do exist in the world of the anime - I just assume just that Ash has never gone there. The Orre games were very RPG-based, so that isn't a very farfetched assumption.

Yes, the Splash Plate was obtained easily, but as you said, in RPG fashion, quest items are easy to get at the start. And consider this: Maybe the strange woman who was watching wanted Starbuck to take it. Try reading the chapter again with that in mind, and you might see differently.