Advice for a noob

Just started playing Bannerlord, and good God I am in love. I have some questions that I hope people here can help with.

For context: I am playing as Aserai. I'm sworn to the ruler of the Aserai and I single handedly conquered most of the Khuzait lands, minus one city. I have 3 cities and 5 castles as fiefs. I got fed up with the King giving fiefs that i conquered to different nobles, and losing wars with the northern, southern and western empire, along with the Vlandians. The tribute payments are crushing me. between all of them its about 7,000 denars a day. So I decided to declare a kingdom and I underestimated exactly how pissed off the Aserai would be. They ended all wars and flooded me with massive armies. I also shot myself in the foot with the Khuzait nobility by executing a ton of them (they captured my pregnant wife and she had a stillborn child while in captivity, so I had to get revenge).

I'm thinking my best bet is reloading to a save before I declared a kingdom, and start actively preparing for it instead of doing it on a whim. I'd like some pointers on how to do that properly.

• What advice would you guys be able to give about stopping the hemorrhaging of money?
• Should I load all my high end troops into garrisons and farm xp with the recruits currently in the garrisons?
• Should I have larger garrisons in the Castles and take them out of the cities to reduce the massive garrison costs?
• Should I wait until my children are grown to declare a kingdom so i can use them as companions?
• Should I stay out of wars, and stabilize my fiefs or try to make up some lost money by joining in the wars?