No, that's where the clue is. "Boys are weird" Sarada said this to Sakura because Boruto has done what he did quite a few times already. Sarada knew that he was going over and draw on the Hokage's faces again and that's why she was looking at him. And what happen after that? She followed him because he was going to cause trouble for Naruto/his father/Sarada's adoptive father again. We see Sakura say, "Bolt, again" because like I said, he's done it a few times already so she knew who Sarada was referring to.
Kishi might be trolling us to make it seem like Sarada is similar to Hinata and that she likes him, but that might not be the case.
And? You didn't get it. That behavior is from someone that isn't close to the other one. If she were her sister, she doesn't need to hide.