this really doesn't strike me as Khan (emotionally and environmentally sensitive?! Worried about having upset Marla, and introspective about whether he's ever truly loved)
The emotionally sensitive part, I agree with you about, although I'll suspend my disbelief and accept as seeing Khan portrayed in a more positive light. In fairness to Khan, he did tell Marla he wasn't used to being asked questions where he had to be introspective.
As far as the world itself, he is environmentally sensitive and that would seem out of character. He should have a "survival of the fittest" mentality, but I'll take the interpretation of he wants to learn the rules of the world before he
makes the rules of the world.
I believe it when he says that on Earth he felt he had to conquer before rebuilding the world. The benevolent part, I take issue with because then at least some of the world powers in the 1990s wouldn't be against him. So I take issue there. I think this is trying to rationalize how the Eugenics Wars happened without devastating our world in the real 1990s. I think
To Rein In Hell took the same approach, though I haven't read it, where they tried to have the Eugenics Wars happening in the background.
Marla (where do I even begin? This is Kristin Beyer feminist Marla, she shares 0% of Space Seed Marla's traits; even just in this episode, she has to restrain herself from arguing with Khan over how he's treating her. I am reminded of Galaxy Quest: "Did you guys even watch the show?" And that's just this episode, episode one was even more of a hot mess for her. Maybe this is how she 'should' have been, but this is simply not who she was, and if you want to try and 'redeem' the character from a modern viewpoint
I'm not going to deny that they reinvented Marla's character, but they did start by responding to her actions in "Space Seed". She was a relative nobody on the Enterprise prior to "Space Seed". I think she's right that Kirk probably didn't even know her name before that episode. I can see her doing very little or interacting very little with the crew prior to that episode, being a Historian and not having anything to do with the missions. Khan is right that Marla was in a prison of sorts herself.
She seemed submissive to Khan in "Space Seed", but she did counter him when she didn't allow for him to kill everyone on the Enterprise. So that is an example of her from that actual episode of standing up to him in her own way.
As far as in
Star Trek: Khan, they made her stand up to Khan more but she's also completely out of her element now. I think she's adapting to her changing circumstances where Khan hoped that she would be stronger and she had to be stronger to survive on Ceti Alpha V. Running out of time, but that's all I have to say for now.