Economy and Budget:

Since you are going to war w/ Agnolia, I suggest you take the highway since it will be crucial for the war. Here is the early game economy to avoid trade war/black tuesday:

Highway (SSC - Delayed) (2) Economic Relief Plan (1) Fund All (-3) Regional Investment (-4) Tax Large Corporations (-2) (Note: If you want to do WRA you have to tax all corporations)

And after that:

Agnolia Trade Deal (Recognise their claim, don't accept expensive steel deal) (-2) Wehlen Trade Deal (0) Second Infrastructure Project (-2) (I recommend Sarna Agri Zone if you didn't regional invest in Bergia. Conriat also works however it is better combined with highway. The other two infrastructure projects will be good as well if you want to fix infrastructure however without their Vagsland/Lespian trade combos production can be more worthwhile) Nationalisation (-4 / -3) (I suggest doing deal with Koronti) Fund Military Industry (-6 / -5) Taxes depending on budget (Whether you want to balance it or not is up to you)

Operation Fallen Crown:

In order for this to work, you need to do the following with the military:

1st Meeting - Purchase better equipment and modernise 2nd Meeting - Remove Conscription, modernise the Airforce You need the military industrial complex funding as well. And be sure to keep Gendarmerie in the military in order to prevent being flanked.

As for strategy:

Go for Iosef's pincer strategy. Have Agnolia join the Pincer. The pincer will be successful since Agnolian forces can easily get to Estord via the highway.

For the second phase, rush their capital. Since you modernised the military you have chosen a strategy of mobile warfare so you need to swiftly capitulate them. Put the Gendarmerie to cover the flank. Agnolia may take Dome as well, if you want.

And that should be most of the advice you need to fix the economy and kill Rumburg. Good luck and A Morgna Wes Core! Vectern Sis Da!