Here's an interesting thought for dwarven economy: Being able to become a wagon in adventurer mode.
Crazy right?
Suppose using advfort a character were able to build a wagon using 3 logs and 2 "pet" horses/cows/ect... then using forcing a character swap, that character becomes the wagon + horses with their former body and whomever they've convinced to travel with them as caravan gaurds. The wagon-creature is able to haul all sorts of crap but has only the usual "hoof of death kung fu" that wagons usually have in fort mode. A wagon that gets killed (ie, the horses/camels/ect... are dead) is "scuttled" and produces three logs of wood once more. Wagons could end up with awesome names, which would make Legends mode a bit... different... too.
Ok, so that all seems a bit reasonable, but here's the next part which might be harder to do:
The wagon decides to retire at a hamlet or something - the wagon "dies", the adventurer pops back into his/her original body and that civ gains the inventory of that wagon as part of their trade goods. Seeing as how using dfhack, fortresses can be made to live on past abandonment, this means that they can in effect trade with each other by having adventurer wagons pick stuff up at one fortress and "sell" it to the civ of another fortress. If those trade-goods are then able to be resold to the fortress in fort mode, they've just become a link in a caravan trade economy. Trading coins would be useful again and kobold/bandit attacks would make more sense as caravan thieves.
Thoughts?