That sounds rather convoluted. I don't think Kishi was aiming for the readers to have such a long chain of thought when he showed the chapter.
What I got from it is that Naruto is aware that his relationship with Sakura is beyond friendship, but since things haven't been cleared up between them he can't answer with a simple "yes" so that's why he adds the "something like that".
Remember that when Minato asked the question Naruto actually took some seconds to think about it and then answered with a straight face. That's not how you draw a person that talks in a joking manner.
I also think Sakura is aware that her relationship with Naruto is already beyond simple friendship, but since they haven't solved their issues she'd rather Naruto not bring up the subject to other people and that's why she got mad at him and told him to not talk. Remember that Sakura at no point denied Naruto's answer.
Sakura figuring out things by herself, dude i really dont know.