Those were ideas. I had a closer look and it's easy in 1.06 to specify if the player can build a certain recipe as port, warehouse, or both.
I unchecked the warehouse versions and I can now only build ports. Saved and reloaded the game, appears to work great.
The map would actually work better with more ports. We can see when starting that Livestock etc. during the 3-year pre-game economy simulation would really like to cross some of the large rivers which on this map are really seas. So the base economy would actually be improved by the player trying to capitalize on their potential.
Only being able to build the warehouses in certain locations is, as you surmised, less elegant in practice. You mentioned adjusting the warehouse bca potentially. My thought was along the lines of significant raise for base price of warehouses, maybe x5 (I would aim for a 50% ROI best-case scenario, need to check how the new price affects profitability via boosted Labor & Overhead and adjust accordingly), then a discount on all industry in the 4 special city zones. For example 50% reduction. Which will let players build the normal industries for half price there.
But, let's remember that these areas are off-limit at the start of the game. Furthermore, the best normal industry opportunities, build on the same cell as a farm, are IIRC unlikely to exist in these zones. Most often resources for these industries would also have to be hauled in. Building next to an established industry and using/stealing it's stack can be an exploit of sorts. However, at present warehouse ROI levels, a 50% sale on normal industries everywhere on the map is actually not that attractive, suppose we see some 80% ROI industries while present warehouses are 200%+. I feel like this "scheme" (if you will) has potential to provide interest and strategy, while keeping intact a lot of the warehouse's existing cargo multiplication behavior.
And of course these are just ideas, with the potential to curb some of the maps ridiculous excess.
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