The entire left side of town is now, obviously, collapsing. So I watch it for a minute to see what's going on. And what do I see? I see a market trader go to the warehouse to buy pottery! WTF? Did it notice me not looking at that side of town for too long and decide I needed to be punished for it? And it was at this point I uninstalled. There's either something incredibly fishy going on here or the game is, quite literally, broken (not the best screenshot, but you can just make out the trader's boy behind the schoolboy at the crossroads) (also, for people tempted to say "crossroads" there is a market trader at the end of each road, they have to walk down the road to get to anywhere else, the crossroads are NOT the issue, market traders are target-led and will always aim for the granary or warehouse):
This my guess from the info available. I would be interested in loading up the save file if you still have it.
Some of the rules governing market buyers:
Market buyers will prefer to fetch food over goods if there's none at their market.
Market buyers will prefer wheat to other food sources if available. (unfortunately not even the manual tells you this, although it does tell you wheat farms produce twice as much as other food sources (depending on climate), making them preferable anyway)
Market buyers can only fetch one type of good at a time.
Conjecture:
Your granary has come to consist mostly of fruit.
Conclusion:
The market buyers spend most of their time picking up only a unit or two of wheat at a time.
Solution:
Remove either fruit or wheat farms.
Remove and replace the granary to empty it of fruit if you went for wheat production.
Result:
Market buyers can fetch 8 units of food at a time and so will have time over to fetch pottery and other goods.
Lesson:
Only make additional food types available to luxury districts that need it.
As for the bath house on the right side of town and the discussion of intersections generally, it's not like the game doesn't tell you in the intro to the very first mission:
As for single-wide housing, in the first mission intro they also show double-wide housing:
Plus, in the first mission as soon as a fire starts and gives you access to prefectures they tell you this:
Clearly indicating the viability of double-wide housing, which is more space-efficient than single-file, which is important due to the walker ranges.
And a couple of other things in that long post.
Now, there are certainly important things the game doesn't tell you and when you run into trouble it does a poor job of telling you what the actual underlying problem is and how to rectify that. A number of the less obvious things are covered in the manual; sadly the manual also has a lot of flavour fluff and a couple of pieces of bad advice, primarily in the fluff. But the underlying mechanics and algorithms are rather simple, they work how they're supposed to and in combination create quite complex systems, the managing of which is what provides the fun for those who like the game. Yet you keep banging on about how the game is fundamentally broken because your suboptimal designs that don't take the game mechanics properly into account don't work well/aren't stable.
You simply seem to want to play a different game with different mechanics, which in the end it seems you did.