I too sent out a caravan a few days ago and it hasn't moved yet.
Also, you're really selling food for 1 gold? Either your region has a ridiculous gold income, or someone is taking advantage of you
Selling for 1 gold can be useful if you're not sure what the buy order is set to and want to make sure it sells to any open order -- if the buy order is higher than your limit, it will sell at the price of the buy order (though I think if there are multiple buy orders for different prices, it will choose the lowest one that is equal to or higher than the limit).
But yeah, also having problems with my caravans on Dwi. Specifically, I set it to automatically send caravans out if I have more than a set amount of food, and it is not doing that. Will try some other stuff.