No, you did not read what I wrote thoroughly enough. Yes, it is about "expectations of [...] fans", but not the "I have been a lifelong fan, so gimme", but the kind of expectation that is created by the plot of a movie. The difference, again, between the topic of Obi-Wan´s parents and Rey´s parents is that Obi-Wan´s parents never played any role in all of those stories he was featured in. The question was never raised.
Rey on the contrary is introduced as a girl with a longing for her parents, someone who is lonely yet hopeful. The parent question is part of what we know about Rey. And the average curious mind IMO does seek answers in such a situation.
Again, a movie is allowed to play with the audiences expectations, but it is a thin line to walk.
Regarding the lightsaber toss, I cannot tell you why but I would have accepted it more if he had looked at it for a shot while, turned around and had tossed it into the sea. If you want to get rid of something, wouldn´t you toss it away for good, especially if you have really bad memories connected to it?