I believe that most of these issues would be solved by giving governors more tools to govern their city. We all want to open the crafting stations to more people but by doing this we lose control of the warehouses. Anyone can enter the city and take any ore, wood, stone, material they would like, so we shut down the city (citizens + residents only). People have their own smelters at their own plot because 1st they don't want to start smelting their Copper, come back 4h later and discover someone else took it. 2nd normally all the smelters are already full with someone else ores and you just have to wait. If you are a casual player will you come 4 in 4h just to see if you were able to be the first one there and finally be able to smelt your 5 copper ores? There should be the possibility of having professions. Citizens dedicated to take care of the Blacksmith, for example, that would take the requests from citizens and residents and manage the smelters and storage of the Blackmith. This can be done at city level by governors, but then they would need a way to set up these permissions.
The governors definitely need a way to communicate with their citizens/residents and know who their residents are. Going with the treasury log does not help as it does not register any resident that may have abandoned their plot. So a city chat or board is definitely needed, and I also liked the idea someone gave in previous posts regarding a possible way to receive mail at the plot. This would assure governors to be able to contact everyone even if they are not online.
Regarding the marketplace the resources need to be more difficult to get. Lock them again by city or find a way like Kralith said (also in https://forum.fracturedmmo.com/topic/13867/town-controlled-area-doesn-t-exist-how-will-that-work-in-future) to enable cities to defend their resources by knowing they are being attacked or stolen. Last Alpha test the trades began even before the Marketplace was built or before they had real buy requests behind. Each one of us had only one resource available so we needed each other. The discord Alpha-trade and the global chat were filled with trading requests of cities asking for a stone wagon in exchange of a coal wagon for example. Money was not the goal or the issue but the resources themselves. It was a lot of fun! Travelling was never an issue as traders would take their full wagon across the map just to trade it with the needed resource for the city. If we already did this back then why not going all the way now to get that resource for free?
Now as a player, let's imagine you are a tank and you need that Blood Iron Plate Armor. Two cities away from you there is a city that already unlocked Advanced Smeltery, Craftmanship and Plate Armor (total of 5 research points). Your city unlocked the Marketplace and (imagining it is not resident/citizen closed) someone put that Plate Armor for sell. Now how much gold would it cost considering you need to farm Iron, Copper and Coal? Let's imagine they sell it for 4k, would you prefer to buy it or just go live in that city where you can produce not only the armor, but the full set and you only need to farm the raw materials? This would also be an interesting poll to allow governors to decide how they want to invest the research points. No one wants to lose residents.