You don't need a detailed plan for your Economy. Currently there is no reason to invest money since everyone begins at 100 prosperity in every single province.
To increase prosperity you need to invest money, simple as that, no complicated plans ala: Start prospecting for mineral resources, close the banks to prevent collapse of the currency or somesuch. You just invest money to increase prosperity.
How much depends on the population of the province and the amount of prosperity. say you are at 90 Prosperity in a province with 100.000 people. To increase that provinces prosperity back to 100 you need to invest 1 ducat per thousand people in the province. So for 10 prosperity 1000 ducats.
Of course that does not prevent you from making fluff actions, that you rebuilt villages, improved infrastructure and done what not, just that its not necessary.
You do not need to disguise any of your actions in pms, that is utterly optional. Raising Troops and moving them both triggers automatic scouting rolls for neighbouring or subjected players, making those movements/raising visible to them.
Trade and tarrifs are not a thing, you can assume they happen automatically already via the prosperity mechanic. (see stuff about fluff when improving your province from above ^^)
No you cannot do renaissance, period. No cannons, No Guns.
Actually let me rephrase that, you can go for it but you won't get beyond those really ancient arquebuses and ship cannons, which were not really an improvement on longbows, crossbows and trebutchets/scorpions. So yeah no tech advantage for anyone
That is to say nothing prevents you from raising some 200.000 Portuzi Arquebusiers and simply going for it. It simply means you won't have a great tech advantage through the use of early gunpowder weapons.
Regions only differ in terrain,prosperity, population, culture and religion...beyond that there is no difference. So if the region isnt interesting due to prosperity or population reasons it might be interesting due to its strategic terrain or because it shares a certain culture or religion with you.
Religions have no intrinsic differences beyond providing unique units for you. So raising a levy in Religion As and Culture Bs territory will give you some different levy units than Religion C and Culture Ds territory.
While certain cultures will certainly excel in fighting in certain terrains (Shwazen in Bogs, Roimlanders in Mountains/Hills and Astellians on Plains) it is not unique to them. So yes you can raise Portuzi Heavy Cavalry who excels at Plains Fighting even more so than Astellian units ever would...its just far more expensive.
So yeah if you raise levies you will also get some info on who does what...and is good or bad at which things.
On the other hand if you raise professionals, you will in all probability tell me what you want so yeah...unless you just want me to provide you with a list of potential things to raise/train/do.
going by this post i assume you are still interested so i'll re-reserve your spot...just got tired of waiting for folks.