Does Sereana really love Ash

I think she's just idealistic, passive and quite delusional. Nothing wrong with that, but she is based on the antithesis of Dawn. She has the romantic spark Dawn needs, but she needs the bond-making capability Dawn has with Ash. Compared to what you see in early XY, Serena is a bit more mature and takes her time. Previously she just dropped her spaghetti all over the place, she still does but not as much. Her character is designed in such a way that it complements and contrasts with Dawn's personality and talents. Serena admires Ash in the same sense that Ash admires Dawn, but Ash is dense. 

Serena starts to like Ash once he helped her in Pallet Town
She drops spaghetti and blushes at Ash once she meets him again, but is too passive to make a move on him
Serena comes close to admitting her feelings to him in the fight and realizes why she likes him. Early XY Serena would have never done something like this.

In short, yes she does. Candy Girl by Shoko Nakagawa is an example of Serena's feelings towards Ash. It was located on a different track as DoriDori, and Shoko Nakagawa confirmed it as being an Amourshipping song. In the song, Serena accepts him for who he is rather than as a perfect person like she did in early XY. But she wants to know who the real Ash really is by saying that she wants to know all of his colors, embrace his strengths and weaknesses in their entirety, etc. Also to draw upon contrasts, this song shares very similar themes with High Touch. Amourshippers interpret this song as something in the present, but a closer analysis shows is that the song represent Serena's aspirations and ideal future with Ash.