Bound village and settlement issues come and go. They will disappear on their own, but like you said, others pop up. Keeping up on them has benefits. It makes your people happy, which makes them feel more secure, which makes them more loyal. Happy people produce more and better recruits when you need them.
This feature existed in Mount & Blade: Warband - Viking Conquest. It was excellent. Reduced troop upkeep iirc. I used one to amass enough men to start my own kingdom in Cornwall. You could also build a dock and keep a ship there iirc. I'm missing that feature for similar reasons. It would be nice to keep elite troops stored up.Relations with the other lords, but also renown and influence. If you persist in partaking in large-scale battles, defending and attacking castles and cities, and accompanying lords as they patrol your kingdom, the vote for a fiefdom will eventually fall to you. It also helps if your kingdom is on the winning side of a war.
You will take losses, but far fewer than with a classic assault. Some castles are more vulnerable to this strategy than others. Battanian castles and Khuzait Castles are particularly resistant to this strategy. Most Vlandian, Imperial and Sturgian castles are particularly vulnerable to this strategy. r/mountandblade. Presumably yes, moreso depending on other negative factors like whether caravans carrying food to sell are delayed/intercepted, the local villages food supply to the settlement getting raided, whether the city had recently gone through a long bout of starvation i.e. after a long siege, and (if you are owner the settlement) having the daily Enjoy the -40 or -80 to everyone though. It's as Jorn Stones says, you're able to leave your kingdom (and retain your settlements) by navigating to the Kingdom tab, and selecting 'Leave Kingdom' in the top right corner (should be a red button.) I do believe the relation amounts are -20 if you leave and give up your settlements and -60 if you vhGg.