I think Kara will eventually reciprocate. And while I look forward to that playing out, I will say though, that for me, as a viewer and even as a fan of their pairing, I'm okay if she doesn't. To be clear, I really like the potential of their romantic pairing, but they're also really good platonic partners. They're banter is lively and entertaining, and they make good foils for each other, so the romantic angle, in my opinion, is a most welcomed bonus.
I'd like to point out, though, a big difference between Mon-El and Winn's reactions. Winn was very upset when Kara didn't reciprocate his feelings for her and cut her out of his life for some time because of it. Mon-El, on the other hand, didn't do that. Mon-El while also upsets, gets that Kara may not feel the same (and really, I don't think Kara knows how she feels either. Girl hasn't even had time to process it all yet), and he doesn't make Kara reciprocating his feelings an ultimatum of sorts on their continued friendship. And that to me is a big difference between Winn and Mon-El.
I thought it was kinda sweet that even though Mon-El thinks Kara doesn't care for him romantically, Kara's important enough to Mon-El that he just wants to be part of her life in any way. I guess I'm a softie, but I thought that says a lot of just how much Mon-El feels for Kara and I liked that he gave her that out.
It'll be interesting to see how Kara feels about it all. Mon-El is certainly not the straight laced type, and he definitely challenges Kara in many ways (frustratingly so for her, at times). In fact, they challenge each other, which I think can be a good thing. But at the same time what makes them good partners, in my opinion, is that those opposing points of view can complement each other. I'm looking forward to seeing how it all shakes out. Hopefully, no matter what, the show keeps Mon-El around. At the very least he certainly keeps Kara on her toes
As for the Shakespearean comparisons, I see it but in my opinion it's not quite the same. For Romeo and Juliet the problem was outside forces - the families fighting against their union - not Romeo and Juliet fighting each other. In contrast, on this show, while Kara and Mon-El came from warring planets, it was a war fought and ended long before either were born and their story seems to be more about them as individuals overcoming their personal hang-ups and prejudices (behaviors that are partly a result of their planets historic rivalry) and building a friendship and perhaps a romantic relationship despite their differing cultural histories.
The way I think of it is that Kara and Mon-El came from planets with diametrically opposed value systems. Krypton's culture seemed to be egalitarian, concerned with justice, democracy, etc., and Daxam was based more on a feudal system that benefited a chosen few, and was more about self-interests, hedonism, and whatnot. It seems to me that now on Earth, Kara and Mon-El are literally in place where you can choose to be either - someone who only lives for personal pleasure, or an altruistic hero (or neither!). Earth provides them a blank slate. Kara knows who she wants to be now and the values she wants to embrace - heroism, truth, justice. etc. and has a sense of the road she wants to travel. It's now Mon-El's turn to decide who and what he'll be on this planet - what road he wants to travel. And I think the choices he now makes - does he default to the hedonist behavior, or truly embrace more altruistic values - will have a big impact on whether Kara and he can build a romantic relationship if not just a genuine and lasting friendship.
I think Mon-El is truly trying to embrace better values - we've seen evidence of it over several episodes - and not just because he likes Kara. Her influence on him is clear, she has inspired him, but there had to be a better nature within him to begin with for her to have any influence at all. I'm remaining optimistic. What can I say, I'm rooting for these two crazy kids to work it out and get together.