Trade is all well & good when its used to fund a war or in an empire builder (such as Imperialism), but it can become so important to the economies of all players that they daren't risk having it cut off. I propose giving each nation a moderate flow of reinforcements via events and a medium monthly income to represent trade. They can increase their cash flow & production ability via conquest. I could even set up a special 'trade' unit to arrive at a random interval in major ports. This unit could then be moved to a city & disbanded for it's shield value. Capturing these ports would be a goal. You could extend this to mining towns which could produce some kind of industrial output and so on. You could even have a 'Merchant ship' created at sea who's purpose is to sail to a friendly port & disband. I'll have a think about what would work best.
It would be good to have some kind of tangible reward for conquest, other than just control of the city itself. A reason for fighting and not just self-preservation, especially for the French. I think all of this could be achieved with fairly minimal work by way of the events. These events are all relatively quick & easy to set up and alter.
I won't attempt to set up any kind of historical events with set dates. That will be up to the players to dictate.
The scenario begins with Napoleon campaigning in Egypt. It been a while since I studies the era and I'm not sure I ever really understood the point of that adventure. This was in a time before the Suez canal. What was Boney seeking from the conquest of Egypt?