Touka too. I don't get the reasoning or idea behind her Christmas present at all. Touka has rapidly become one of my favorite characters in this, and she went from naïve bumbling but super kind to all knowing mommy in like...no events. There was no progression to the point she is at at the end of this update. "You are not going to hide from your emotions in me". She has had very little social experience and she is spitting lines like this? And she buys an entire apartment building and doesn't consider Chika's situation at all?
I agree with a good bit of what you posted, but not so much here. Her reasoning with the apartment is off, at least how she expresses it, but there's a history of the whole family having no real concept of money. That much being thrown at what's currently a poorly thought through plan to get closer to someone she likes isn't necessarily bad writing, assuming there will be a bit more context in time..
Chika wouldn't really factor in here any more than she would at any other point (though I do wonder if she might end up with the place eventually).
The emotional aspect is a bit more complex, but she does have some history of being unusually insightful in some way or another. If she can figure out a fairly reliable way to make Yasu chill out on the insane zealot stuff for a bit, I don't think picking up on some of Senseis weirdness is that out there.
The kinda precocious or mature takes being tied in with being incredibly naive about a heap of shit is present in the whole family, in one way or another. They're all clearly meant to be smart and able to pick up on stuff, they just are crazy sheltered.
Does kinda just comes down to how it's handled as the plot moves forward, but I think it's at least somewhat consistent with what we've seen so far.