Regardless of her sexual orientation, Chii's volatile and, dare I say, delusional nature really overshadows the redeeming moments she's had. Such a dramatic shift from her early counseling of Seto is only believable if one takes the stance of her being irrationally consumed by her fear of change. Now, that's not unreasonable, or bad writing, just... Tedious to wade through. I absolutely love this manga, but I feel its currently in danger of "overdoing" it with Chii to the point of making her unsalvageable. That is to say, who cares about her growth and "redemption". Its safe to say all the characters have a fear of change and progress to different degrees, but Chii resists so much more than any of the others, and for less demonstrable rational reason that it becomes irritating rather than endearing.
In the event Chii IS gay... Its disappointing in that she's essentially just another stalker, "just a friend" cliche character. I would honestly be surprised by that, and feel it was a wasted opportunity. Apart from feeling bad for Tokio, I would mostly be indifferent.
I'm much more invested in the other two pairings, but best of luck Tokio... May you get what you ask for, hopefully you want what you get.
As ever, thank you for scanlating.