So Ayano still being super annoying and not caring about anyone's feelings but her own. Even if she where to spend time with Masatora alone he is not going to change his mind about Amane. Masatora has never cared for Ayano in that way why would it change know that he is dating Amane.
Yes because you are asking Ayane to bury her own feelings to not inconvenience Amane.
And you want what? for the main couple just cruise around without any issues, what a boring story that would be ... I have no patience with people that think you can write a story
about nothing since as you pointed out Amane and Akutsu are a couple and there is nothing threatening their relationship, they going around having dates would be incredible boring and we know this because no series does that or if it does, it either ends or creates something to threaten their relationship.
The truth is the story ended in the rescue Amane arc were everything apparently got solved, the threat that was Amane family is over and even if there are unexplained parts about both Amane and Akutsu nothing of those parts seem to be a issue, if not for the comedy this whole arc would be dragging for too long and in fact is because the author really doesnt have a place to go with the story, Ayane is simply carrying the role of the "villain" to extend it, we all know its going nowhere and even Ayane victory could be seen since it does cuts down Amane a peg down over her "winning", if anything Amane and Akutsu dating was too soon as it cut the story legs down.