The big picture is done (give or take), showing all available dialogs, actions, etc though the road, along with respective interconnections.
Some items were simplified as it felt too much to work out all mechanics in this endeavour.
With this picture, it is now clear which pieces (mechanics, items, dialogs) are missing and overall it now looks feasible to complete it all.
Next I'll get to the 'ladder' which Ryo would climb during his wandering.
Here is a sneak peek of it (sploiler-free due to low resolution):