Kingdom Management Tips N' Tricks:
1 - Level up your advisors as soon as possible. Make sure to do it early in the month because you don't want the 2 weeks auto-time pass to take you past the end of the month where events will auto-fail. Leveling up advisors means getting your kingdom stats past levels of 20s by building things. For every 20 stat in your kingdom you get to level up the advisor in charge of it, giving them better rolls and higher success when dealing with events.
2 - Spend the first few days of the month assigning tasks if you aren't leveling up your advisors. Then when they are busy, go adventure until the middle of the month or the 20th or so. Head back to the kingdom late in the month to assign any last minute events. This is how you balance time adventuring with kingdom management.
3 - Sometimes NOT doing a Problem event is better than attempting it if you know you will fail. If it has a really high Difficulty Check (DC), and you send someone who will likely fail, you could roll a bad number and have not just a failure, but a disastrous failure, which really hits your kingdom stats hard. Sometimes it's better to ignore those or take a sure bet Opportunity with a lower DC than a Problem with a really high DC.
4 - Try to stay in positive BP. These are your kingdom's coffers, and the people are happy when you have money in the bank and aren't broke. Also try to keep your stats evenly balanced if possible. The people react to the kingdom stats, so if your Stability is low, they will understand that and not be happy about it. Also, try to advance your kingdom stats to 60, where you can potentially unlock a new advisor position by leveling up the previous advisor. Check the kingdom stat tooltips to see which stats will add new advisors. Each stat has an advisor that you eventually unlock for a total of 10 advisors.
5 - If your kingdom is in shambles, feel free to pawn a lot of the magical items you've been hoarding but not using in order to throw a feast for the townsfolk. This will raise your kingdom status one rank, so if you're crumbling, it will go to riots, if you're in riots it will go to troubled and so on. This buys you valuable time to continue working to restore your kingdom.
6 - You can turn on Invincible Kingdom and play on Normal difficulty for Kingdom management. Invincible Kingdom simply means you can't lose by being in "crumbling" status and messing up, you can only lose by not doing the main quest in each chapter in time. When your advisors or someone warns you of a terrible looming threat, you must devote your time to that. You can still lose the game if the main quest isn't finished in time, but at least you can't lose if you're stuck in "crumbling" status from messing up previously.
6 - Again, feel free to explore in the early and middle parts of the month. Don't abuse the rest system, use scrolls, potions and spells to compensate. You can explore all around and find little hidden nooks by having high Perception which will open new areas on your map you previously couldn't see. There are many spots that are small maps but have little stories and magical loot with a tough encounter, and that will help you to acquire new magical items to sell or use.
7 - Buy BP sometimes from Hassuf in the capital. This gives you an edge to build quicker and conquer lands quicker. That means you can get more economy flowing in and also keep the people happier as you expand your kingdom. Selling magical items you've been hoarding gives you tons of money for BP, so use it to your advantage.
8 - Beware of really long projects that take 90 days. They could be very useful but it's hard to send someone for that long as you may miss out on good opportunities that only that advisor could handle.
9 - Don't abuse rest during a crisis. Every moment is critical then, so do your best to only rest when absolutely necessary, otherwise you're passing time and the status is getting worse as you do. This was a big mistake of mine. The game expects you to only rest when you really need to. Also, use rations instead of hunting sometimes to save time on your rests, since hunting can take 10+ hours sometimes.
10 - Travel light whenever possible. This saves time traveling and your characters tire less, letting you gain precious hours and days before having to rest.
11 - Seizing new lands mean you can build settlements there, which will help you build new buildings that increase your kingdom stats. The more buildings you build, the higher your kingdom stats become, thus letting you rank up your advisors.
If I think of more I'll post them. I'm playing on Normal Kingdom difficulty + invincible kingdom, at least until I pull myself out of the hole I built in Chapter 3. I really screwed up there by not heeding the warnings and thinking a dungeon was too difficult when it really wasn't, so I wasted time by exploring other areas while a huge and dangerous epidemic was sweeping my land. Not smart. Once I'm back to normal with the kingdom, and this takes time mind you, it's not instant unless you throw a feast, then I'll turn off Invincible Kingdom again.
Good luck! I'll post more later if I remember more. Hope this helps you guys!