Kirito always had choices. While not every choice could completely resolve the situation—likely due to Fujino's development constraints—even in scenarios where he's led around by Sinon or Alice, there are plenty of justifications to argue it wasn't cheating.
For an adult game, these explanations are persuasive enough. At the same time, he clearly feels guilt over it. As for whether these plot elements dilute the NTR experience? That's subjective. Personally, I'm all for it.
As for Asuna, I’ve already explained this earlier. What we see is Inoda raping her, but in reality, it’s more of a half-willing sex—the ‘rape’ element accounts for maybe 30% at most. A lot goes unspoken in their dialogue. Let’s be honest—many couples’ first sexual experiences involve some degree of coercion.
As for why she hasn’t broken up with Kirito: sure, he saved her life in SAO, but also... women can be greedy. What downside is there for Asuna to keep him around? At least for now, Kirito hasn’t done anything egregious enough to warrant dumping him.
From what I’ve observed with cheating wives and girlfriends around me, even when they’re head-over-heels for their affair partner, it’s extremely common to maintain the facade of a stable relationship with their original partner—until, say, the man finds out, and then she calmly ends things. So no, I don’t see this as a plot hole.
Given Fujino’s hints, Asuna might start considering a full breakup with Kirito. She’s already wondered—in that hazy, half-conscious way—what if she’d met Inoda first? It’s all down to how Fujino develops this thread.
As for Sugou, I genuinely see no need for further discussion. His hatred for Kirito requires only one justification: male instinct in competing for a woman. Back in my student days, I too harbored hostility toward every guy who approached my crush.
And who claimed he doesn’t resent Asuna’s father? Just because he didn’t burst onto the scene yelling, ‘Old man, I’ll kill you!’? Come on!