Some more points:
1. Is there some way for the dungeon master to learn the books? With the amount of girls coming, there is one male master and 10 girls in my dungeon, each needing the more rare books with the good positions. And the amount of (rare) position books in the market makes it more fit for the (less) males learning them.
2. A setting to adjust the male/female/futa ratio invading/birthing would be nice.
3. About the throne room relocating: this works only for the throne room and deletes the other room. After the first 6 or so rooms i would've liked to move the gold mine with 4 upgrades instead of losing it... And the point with walls/locking doors still stands.
But good job, your "monsters" being cute girls makes you want to buy the expensive gear for them, keeping you motivated. And the personalities fits them to a T.