Once a feudal lord grants a land/title to someone as their vassal it has a double edged effect on one hand they can govern way more effectively but demanding it back is harder, by governing not only over land but people the vassal gains access to creating their own private military force and can start forging alliances with other feudal fiefs whether they be fellow vassals or outside of the realm, other vassals are practically incentivised to take up arms against their lord in rebellion when one of them is at risk of being stripped of their lands because if they don't they may be next and the more they allow the less they can resist when it's their turn. This can be said to be a major factor why in our own history the Holy Roman Empire remained such a loose decentralised state of countless tiny fiefdoms.If Remilia truly develops her village into a rich and prosperous place, won't her father simply take it for himself? The place is under her supervision now, but it's not like it would be her own fiefdom. She only asked for the authority to run it, in her deal with her father, the duke. To have to actually belong to herself, it would have needed to be separated from the duke's lands, and Remilia would have needed to be made a noble of her own house, for example a baronetess if they had wanted to go as low as possible, considering her status. The separated land would then be her fiefdom. However, would the king have made her the head of a new noble house, considering she was being exiled in disgrace? So, currently she's nothing but a duke's daughter, and basically everything material she's not carrying on her person, could be said to benefit her father, the duke.
This needs to be addressed one way or another. The matter is greatly complicated by the fact her parents dislike her and the royal family placed their bets on the Star Maiden, alienating Remilia. So, if the royals suddenly took Remilia's side, it would be the same as confessing they were wrong before. It's a big deal for royals to admit such a thing.
Yes, that's a fact. My problem with this story is that Remilia was never granted a title, and thus not granted the land permanently, but the story acts as if she was. Like you said, it's a big deal to grant that title/land, and may require the king himself to put his name on the paper, but Remilia has a bad relationship with both her parents and the royals. The duke just wanted to get Remilia out of sight, which is the opposite to rewarding her with title and land.Once a feudal lord grants a land/title to someone as their vassal it has a double edged effect on one hand they can govern way more effectively but demanding it back is harder, by governing not only over land but people the vassal gains access to creating their own private military force and can start forging alliances with other feudal fiefs whether they be fellow vassals or outside of the realm, other vassals are practically incentivised to take up arms against their lord in rebellion when one of them is at risk of being stripped of their lands because if they don't they may be next and the more they allow the less they can resist when it's their turn. This can be said to be a major factor why in our own history the Holy Roman Empire remained such a loose decentralised state of countless tiny fiefdoms.
Not necessarily while there's been no specifics about being granted the title officially the people are already loyal to her and in practice she is basically the baron, the more she develops the land the more she politically establishes her position, less like a governor and more like a Regent for this specific part of the realm. To take it away easily from her they would have to do so before it's too late, and too late can sneak up on them before they know it, especially as she's already swaying those that are to keep an eye on her to her side compromising information of how quickly the situation is changing.But honestly, how it all seemed to happen in the story, that Remilia merely is the caretaker of a remote part of the duke's lands, already fulfills all the conditions sufficiently. Furthermore, if by some miracle Remilia became valuable again, she would still be the duke's daughter and thus available for use. If she actually managed to develop the land under her care, it would mean a part of the duke's lands got more valuable, which is a pure win for the duke. After all, Remilia is, at best, just a governor, who can be fired or replaced at the duke's pleasure.
Technically she could have the whole kingdom against her if she started rebelling. If she was formally a noble of the kingdom, having the name of her own noble house in the records, then suppressing her would be more difficult as it could set a dangerous precedent all the other noble houses would be wary of, lest it happens to them next. But if she's just a governor, it's an internal matter to the duke's house, and it hasn't really got anything to do with anyone else. However, if Remilia suddenly got so powerful even the duke couldn't handle her, the king might not like it either. Naturally if Remilia got the king on her side, like by bribing, the duke might not be able to do much. Unfortunately the Star Maiden is poisoning the king's court, and she hates Remilia's guts.Not necessarily while there's been no specifics about being granted the title officially the people are already loyal to her and in practice she is basically the baron, the more she develops the land the more she politically establishes her position, less like a governor and more like a Regent for this specific part of the realm. To take it away easily from her they would have to do so before it's too late, and too late can sneak up on them before they know it, especially as she's already swaying those that are to keep an eye on her to her side compromising information of how quickly the situation is changing.