Political online game and economic simulation

The budget is now balanced, the economy is performing and political support is much more stable. I have three challenges.

I would like to increase the export surplus. It has fallen to just under 40 billion. What are the levers here? Tariffs, education, state visits or what does it depend on?

I would like to launch the Personal Transit Rapid project. 1800 billion is a hefty sum. I cannot assess the benefits here in the game. How do you rate the project in general? Should I start the project or wait?

I have constantly lowered the interest rates slightly. That eases the burden on current interest payments. I have not lowered too quickly so as not to cause negative counter-effects in other parameters. What are the negative effects here in the game if I reduce interest rates?

There are many tasks that somehow affect the tradebalance as well as the magnitude of imports and exports. Other state variables such as international reputation, not all of them visible to the player, certainly also play a role.

That being said, other countries for the sake of trade/exports are only simulated and not actually modelled. Increasing exports are also not always a good thing, as the undlying cause is sometimes a reduced demand within the players state, e.g. due to lower value of the currency and/or lower net income. Vice versa, an increased demand and therefore lower exports can be a good thing.

It is one of the most commonly implemented projects and for good reasons, as it will significantly improve the infrastructure in your state. The invested sum will partially translate into economic growth, as subsidies would do. However, you may want to get rid of more of your nations debt before, in order to have additional funds at hand.

It depends on what you consider to be a negative factor. People will be more willing to take loans, which will increase the debt rate. Capital flight will increase, but so will investments. Furthermore, lowering the interest rate will encourage inflation.

Tariffs obviously. If you increase the cost of imports, imports decrease.
What state visits?
Education, yes. It increases the productivity of the nation in the long run and more can be sold.

Taxes: If you increase excise taxes, people in your country can afford less and more can be exported.
Exchange rate: A weak currency increases exports and decreases imports.
Subsidies also should help, but might decrease prouctivity.

But as MrProper already said: Imports aren't bad.

Btw, there's a German Fragen und Antworten.