I have never bought or made adamantine or sold it for that matter. I get enough through disassembling found item and dungeon finds. Same goes for dragon bone. Most of my high end tools are ancient bone and mithril. Not the top but more than good enough. It seems to me that both adamantine and dragon bone should be rare. Now I dungeon delve a lot. Later in the game I do 3 hard dungeon a day. Someone who has more slaves could do more.
I rarely have more than 20 slaves,. A large number may be important to some players, but its not crucial to the game. also, its easy to mod in more rooms. There is already a mod for that.
Maverik says that in the next version only the Growth factor can be raised. So eventually it can be 6 for many slaves. But the other factor will remain the same as at birth. Gives an incentive to careful breeding and weeding.
All of the high tier weapons require two hands. It does make shields and the spell book seem useless.
The Oblivion potion is useless. It doesn't return experience points or allow new classes to cost less. Purely cosmetic, for those who don't like to see a sex toy with the knight class or vice versa.
The game is relatively easy to mod. This can allow players to tailor the game to their preferences while the developers focus on more basic game mechanics.