a poet trapped inside the body of a finance guy

“Maybe someday you’ll come with me to those fields. They are neither as wide nor as rife with purpose as your precious sea. But in the right light, in the right company, they might be beautiful.”

Kaz bought the farm he and Jordie grew up on and he wants to bring Inej there???

He did not allow it, he had to carry out an order from the queen, who wanted her. 

The queen did not order The Darkling to provide her a grisha tailor. Her talents showed themselves at an early age and she was gifted to Tatiana Lantsov by The Darkling.

“When Genya’s abilities began to show themselves, I could have had her choose between becoming a Fabrikator or a Corporalnik. Instead, I cultivated her particular affinity and made a gift of her to the Queen.” - Shadow and Bone, Chapter 7 “The Darkling had given me to the Queen” - The Tailor

Do you know what orders are? Darkling himself had to obey them. That is the first thing.

Obviously, everyone must obey the orders of the King and Queen, including The Darkling, but you are minimizing his obvious high-ranking role in the Ravkan government. He is the general of the Second Army and in charge of all grisha, he has been for generations of Lantsov Kings. He could have chosen to keep Genya as a tailor under his command, to wear his colors, or give her a new set of embroidery as a corporalnik, like he does at the end of Shadow and Bone. He could have chosen for Genya to become a Durast or a Healer. But he saw an opportunity to gain a spy in the Grand Palace, and he took it. 

Another point is that when Genya came to him and told him about it, he allowed her to leave... Yes, things like that do not just happen for a soldier in active service. But Genya refused and chose to take revenge on the king. You should acknowledge that as well.

You say this while ignoring the whole premise of the first book, and the power that The Darkling had over this entire situation from the beginning. He is powerful, and is part of the reason why Genya says this to Alina: 

“Alina, the Darkling doesn’t notice most of us. We’re moments he’ll forget in his long life. And I’m not sure that’s such a bad thing. Just ... be careful.” I stared at her, baffled. “Of what?” “Of powerful men.” - Shadow and Bone, Chapter 14

Genya, just like Zoya and Alina, was groomed into believing that they could be one of The Darkling’s greatest assets in the Second Army. Yes, Genya chose to seek revenge on her rapist, which I don’t disagree with, and I would never blame her for choosing that. I would make the same choice in her position. This isn’t about Genya's choice; it is about the fact that The Darkling placed her in a vulnerable position where he knew, the Queen knew, Vasily knew, everyone knew (except for Nikolai, apparently), that Alexander cornered servant girls and raped them. The ‘choice’ that The Darkling gives her is an impossible one; she even says so herself:

"I’d told myself I would be dignified. I would plead my case rationally. But when Ivan closed the door. I started to cry. The Darkling might have chastised me or turned his back. But he put his arm around me, sat me down at the table. He poured me a glass of water and waited until I was calm enough to take a gulping sip. “Do not let them humble you,” he said softly. I’d had a speech prepared, a hundred things I wanted to say. All of it went out of my head, and I sputtered the first thing that came into my mind. “I don’t want to wear this anymore,” I pleaded. “It’s a servant’s uniform.” “It’s a soldier’s uniform.” I shook my head, choking back another sob. He leaned forward and wiped the tears from my cheeks with the sleeve of his own kefta. “If you tell me you cannot bear this, then I will send you from here and you need never wear those colors or walk the halls of the Grand Palace again. You will be safe, I promise you that.” I looked up at him, not quite believing. “Safe?” “Safe. But I can promise you this, too: you are a soldier. You could be my greatest soldier. And if you stay, you can endure this, one day all will know it.” He lifted my chin with his finger. “Do you know the King once cut himself on his own sword?”  A little laugh escaped me. “He did?” The Darkling nodded, the barest grin playing over his lips. “He wears it constantly- just for show, mind you. He forgets it is not a toy by his side, but a weapon.” His face grew serious. “I can promise you safety,” he said. “Or I can promise to see your suffering repaid a thousandfold.” With the pad of this thumb, he brushed a stray tear from beneath my eye. “You decide Genya.” That choice was hard, but this is an easy one.”  -The Tailor

All this Genya even acknowledges in King of Scars when speaking to Isaak:

“But to be a favorite of the queen,” said Isaak. “That must have been a great honor?” Genya popped a slice of plum into her mouth. “For a time, I was the queen’s doll. She would dress me in lovely clothes and brush my hair and let me sleep at the foot of her bed and sit beside her at meals. I watched the sharks and learned. When I grew older, and I had the misfortune of catching the old king’s eye …” Genya wiped her fingers slowly on a linen napkin, the leavings of the plum staining the cloth. “I convinced myself that the suffering I endured was an honor because I was the Darkling’s soldier and his spy. He trusted me above all others, and one day all would know the good I’d done him. He could not have managed his coup so easily without the information I fed him.” Isaak stared at her. “You are confessing to treason,” he whispered. “Sweet Isaak,” she said with a smile. “Nikolai Lantsov pardoned me long ago, and in that moment he earned my loyalty forever. The Darkling threw me into the water, then watched me drown to serve his own purposes.” “So he was as cruel as the stories say?” “Cruel? Oh yes. But he didn’t leave me to the king’s predations to punish me. He just never even considered my misery. What was the anguish of one girl if it might help to earn him an empire? He was playing a long and complicated game. It was only when I dared to think for myself, when I interfered with his grand plan, that he set his monsters on me and—”- King of Scars, Chapter 23, Isaak

Darkling is not a villain either, but seeing that requires some historical knowledge and emotional maturity, which you clearly lack as well.