Eternally Jaded
Superstar
Western developers are more focused on keeping the game simple to understand, depth is usually seen as unintuitive, a Western game developer likes to automatically assume the gamer is as dumb as a box of rocks, as evidenced by their philosophy on tutorials. It makes sense, if I was a game developer I'd probably develop the same way.
Japan kind of assumes that you know what you are getting into and are willing to give in to the craziness of that particular game, even if it's unlike anything you ever played before, and will put in mechanics that some may see as too niche or unique.
Arkham when it dropped was widely considered to be just an extension of what Assassin's Creed already started with it's combat engine, and I tend to agree with that notion. Don't see it as revolutionary at all.
Yup to basically everything you've said here.
The west largely prioritizes standardization of inputs and cues, while the east comes at it from a tinker touch pov.