We both agree on inter-civilization barter. It makes more sense then free trade currently employed in modern world. We cleared the lost in translation meaning of toll/tariff. Yes, it can be a form of tax, but also a fixed sum or a flat rate tax as well. Toll/tariff in this way is already created and used in DF during play to move mountain home around. We agree how valueless are coins without a need for foreign currency reserve.
We certainly do not agree on definition and handling of
strategic resources.
Food is strategic resource in modern world. Not in DF. Caves always can provide farm land and wood land and some at least murky pool water. You are convinced you could turn abundance on every embark of these resources into their sparsity. Enlarging food consumption. Enlarging plot size requirement. Making farming more labor needy then shepherding is. In real life herding animals is more labor requiring then farming btw. Putting wall around pasture in DF alike in real life removes a lot of labor necessity with animal herding.
Logs are resource, which could be strategic alike food. Specially in mountains or on ice embarks. Beds? Yet again caverns are striking back with under ground trees and first caravans don't even trade in logs.
Water could be a strategic resource. In real world, there is always some depth on which natural water aquifers always appear. You could require water for alcohol production. Aquifer can delay players digging for adamantine and lava for longer time. Digging metals, flux stone and gems out of aquifer is a tricky business. Digging deeper could present issue with high temperature instead of water aquifer, but heat is not radically rising when you dig and lava flowing up in stone does not automatically melt the stone either or overheats it. Methane gas aquifer could provide more efficient stop for deep mining, but you need to introduce ventilation pipes into DF. It would look like this in layers: soil - stone - water aquifer stone - methane aquifer stone - lava - hell. Are current deep caverns impossible due missing pressure and missing ventilation?
Metal is currently abundant in DF due smelting bug. Wafers in value of 1/10 bar for other metals then adamantine could fix this bug. Metal alike logs, food and water/alcohol is currently strategic resource in DF, because of hostile environment with FB and sieges. Even if metals are abundant, alike gems they are not infinitely generated.
Gems are not strategic resource. They are not needed. Their only value is weight-value ratio and their rarity, which is limited and comparable with availability of metal ores.
Strategic resources in modern world are also oil, gas, energy.
We agree that Treasury Vault, shops and different civilizations' trading depots and caravan transformation from traveling shop into moving goods logistic will be needed in economy release and definded together with it. Whenever it comes in far far future away.
Though Treasury Vault could appear already together with joining stacks mechanics and work more or less like kitchen does right now. Though what defines Treasury Vault? It could be location based on zoning with assigned Dwarven treasurer, special "treasury workshop" and special container "safe". Though delaying it for economy release makes sense as well. I would wait however with that until location-room definition in DF gets little more improved. Currently when I have 20 master quality A-instruments, 20 master quality B-instruments and so on... I can NOT individually assign particular master quality instrument to a given location. So there is some polish left to be done to location interface at least. Introducing locations for farming and shepherding could be an idea. Location for an elaborate silk farm makes sense too.
I think value should be phased out and replaced with quality. This number determines the priority of two items that meet the same demand and can be modified by % according to different tastes, it is otherwise ignored. If there are two chairs, the entity will bid for the highest value chair (from it's perspective), it should not however ever trade away it's food for a sum total of chairs of a greater value as is presently the case. Really in Real-Life, value is just 'the amount of money I can trade that for', not something that actually exists as the basis of anything.
While regular items may be used as money, regular items are not considered money unless designated as such. Paper for instance is entirely valid as an option for money, but at no point does the civilization simply treat the value of money and the value of paper as the same. Instead the civilization takes some of it's surplus paper and then marks it in the game as 'this paper is money', same with gold or whatever. It does so when it does not have anything else to do (all demands that it can meet are met) and it works because it will trade money for anything else that it has a demand for, including potentially paper to make more money with.
Regular items are considered as money, only because of their strategic resource value. Cave-less mountain embark may have urging need for importing food and logs, while regular forest embark without metals may have urging need to smelting 500 metal chairs in lava.
The quality consideration does apply to artifacts, but for regular items you have no option to order production of only master quality beds, which then you can order only master quality encrusts. Workers cold require to use more materials to achieve that quality, but then it would need depend on their skills and workshops do not allow to just train skills without using excessive amounts of materials and without creating in this process entire mountain of sub quality products. There is also no way to remove encrusts, just to redo them.
What is higher quality really? Just a more fancy item. The only way you would go for more fancy items is, if you have extra resources you can waste, or if you making a collection for some sort of museum. Higher quality does no strategic resource impact. It is basically useless artistic aesthetics. If you are on Sahara, even if this high quality item comes with high price tag, you rather need water and you value water more then this almost-artifact quality item.
Sorry for my strategic resource rant...