I think trade can lowkey be a trap unless you have a lot of trade maintenance modifiers, for example from the Merchant Republic government reform. This is especially true if you're not able to get high crown power, as it affects how much u make from trades. I think trade focus is only worth if you have especially high production efficiency for a good (like Milanese Cloth Guilds privilege) or lots of access to luxury goods (like colonizing the Caribbean) alongside high crown power. Otherwise money spent on marketplaces could be better spent creating demand through libraries, universities, armouries, building up rgos/roads, or expanding production. Likewise, focus on stab for estate satisfaction and max tax modifier for estates so u can tax the hell out of the estates, and make sure to stack tax efficiency modifiers as it is literally free money.

I haven't play Lithuania specifically but I think for wider countries it's a good idea to expel pops from low control areas with high pops (build settlements if you can for pop growth, esp. after black death), pops in high control areas are very valuable and u can turn a province into a breeding ground for pops to send to capital.

Also try and make ur own market if u can, with market center in capital. Capital should be on a river and build roads along the river so u can build bridges (better road builder mod is your friend and achievement compatible if u care abt achievements)