In the real world, she's bound by her protocols and is essentially exploiting a programming loophole to keep them in the framework, where she is decidedly unbound.
Is she, though? I noticed that "Ophelia" herself hasn't directly killed any of the real live people in the Framework; it was Fitz who killed Agnes, and it was May and Fitz who called in the airstrike that killed Mace. The fact that Ophelia/Aida has arranged things to put two real humans in place as her key operatives, the ones who actually do the killing, suggests that maybe her own restrictions on killing are still in place in the Framework. I think she's free to do whatever she wants to the virtual people within the Framework, since they technically wouldn't count as human under her programming blocks (although I consider them to be sentient beings), but when it comes to the SHIELD agents, Radcliffe, and Agnes, she's still been restricted and has needed to get them to kill each other.
As for why she chose that role for herself I think it should be obvious. In the real world she's a slave, so why wouldn't she want that role reversed in her own domain?
Naturally. More pragmatically speaking, she needed to put herself in a leadership position within the Framework so that she could direct all its resources toward her own goals.
It also has the upshot of keeping her close to Fitz, whom I believe she does have true affection for and whom she needed to help her figure a way out of her predicament.
I'm not convinced of the affection. It's not out of the question, but since so much of Aida's and Ophelia's apparent attitudes have been deceptions, I don't trust any of her apparent sympathies to be real. She could be motivated solely by Fitz's usefulness to her goals. As she said this week, Fitz is a romantic, and that's how she's gotten him to do what she wanted, by casting herself as his lover so that he'd move heaven and earth (almost literally) for her.
As I said last week, with the Darkhold in play, it may not be quite as simple as that. The framework itself could be real in some sense. A little pocket universe like the mirror dimension or something. So those people could all be "real".
I agree, in the sense that "reality" doesn't require physical substance. A digitally simulated mind that was identical in structure and complexity to a human brain would have a human consciousness, since that consciousness is a function of the organization and activity of the brain rather than its physical composition. We were told that Aida used the Darkhold and the processing power of computers all over the world to turn the Framework into an exact simulation of the entire planet Earth, equal in complexity and detail to the real thing, so that makes it functionally "real," and its inhabitants are just as sentient as flesh-and-blood humans.