Now the other idea from me: Personal Banking system
I know that the only way to keep a minimal amount of money on you at all times is to deposit into your Town/Nation's bank. But, you would need the Mayor active and online to retrieve funds as needed. With no active Mayor, or ill times for your login, withdrawals would be impossible.
My idea, if possible to implement, would give each player a Personal Bank to deposit and withdrawal from. Giving them instant access to their much needed funds.
Now I know most will say that the "%" used to calculate money lost would prevent a lot of money from exiting the game. I say increase the "/Shop" costs for purchases and decrease the buy back prices. This would generate and in and out flow that is a little more stable and prevents the stock piling of cash in the first place and would push more travel to other Towns/Villages/Nations for quick access to needed items/materials/goods. Also, increasing the cost of TPing to other Villages/Towns/Nations from 20 to say 250 or greater.
Also, in lieu of Villagers, I suggest prohibiting the herding and localized breeding of Villagers for personal/Town/Village/Nation usage. As this grants near free access to Tools/items and resources with little expenditure of funds.