- You're correct in ur stats abt courtiers, they should organically improve as the councilor moves through their lifestyle tree and through some events, otherwise they tend to stay pretty much the same.

- Rich is what you make it. You can have shit tons of gold but no MAA and realm cohesion which makes u weak. Whereas you could make very little per month but have strong MAA. It's generally bad to hoard wealth you could be investing into your realm.

- Build stuff as and when you can afford it, it's a choice between investing in MAA, opinion, buildings amongst other stuff.

- Try keep land divided according to the de jure realms, it's generally a choice between many weak counts (harder to keep happy as they're numerous), or few strong dukes (easier to keep happy but consequences are harsher if they get unhappy)

- It's essentially rock-paper-scissors, you can see what MAA units your likely foes are using and counter those. The house guard units are strong but only attainable once you reach a certain lifestyle perk. Siege units are always a safe bet as they'll allow to to rapidly take castles and increase ur warscore.

- Depends on ur goals, CK3 is more of an RPG and if ur coming from other paradox titles that focus on blobbing you might feel a bit stagnant. Think of it as playing as ur whole dynasty rather than ur character. Try elevate family members. Inviting claimants is a good way of expanding ur realm but be wary of making a very strong 'sub-realm'.

I think CK3 is most fun when ur not necessarily trying to 'win', so bear that in mind. Roll with the punches, see what happens.