As for the one with Sakura, that led to a guilt trip, cause because Sai jumped the gun, again Sai, isn't all that clever, his emotions were repressed while he was in ANBU Root, so all his observations are based on inexperience.
I will skip the next one until I find it again, because I forget where the chapters are, most times, as for making him happy, it is most likely that Sakura achieving in her own chosen field makes him happy, but it doesn't mean anything romantic, remember this is coming from the same person that has rejected him over Sasuke.
and that look, how many times has Naruto said he would never joke around Sakura? before he says that he angers Sakura to the point that she hurts him, then we get that little line, he knows how to anger Sakura, just because he says I better not joke around Sakura or else she will kill me, it doesn't mean too much in a romantic light considering the fact that Naruto knows Sakura loves Sasuke.
Also Sakura is still in love with Sasuke until proven otherwise, and there is no evidence to suggest that point, before you use that fake smile thing, that happened after she happily greeted Sasuke which was 5 minutes before that fake smile, a person doesn't move on that fast, but for Naruto he has had plenty of time to move. that I will divulge a little later on.
okay let's start explaining.
the first one Sakura was telling Naruto that reading is as important to a persons training.
the second was trolled, because it ended up being Kakashi feeding Naruto and not Sakura, plus it was during a time when he still had a crush, which right now has faded.
third Naruto never returned the hug, he could have at least returned it, and plus Sakura was only thanking Naruto for saving the village, it was purely platonic.
fourth well that is the easiest of these little pictures, Sai had no right to tell Sakura that Naruto loves her, in fact that was what ended any chances of NaruSaku occurring, (that isn't being arrogant either) , in fact he was proven wrong and admitted he was wrong, you forget one thing Sai doesn't know anything about basic and complex human emotions, he gets all that information from books, and he is a love expert? i don't buy into that, Sai, is like Yamato, Minato, Gamakichi and Konahamaru, a third person POV that got it wrong and found out moments later.