1-Good connection between the couple. I'm not liking the odd light skimming across their faces though--his forehead looks pretty hot, e.g.
2-This is subjective and not exactly critique, but this photo seems very pose-y and odd. Putting the gent up high makes him tower over her; the bending at the waist to kiss her seems to suggest a goofy tone, but the rest seems so earnest. On the plus side, she looks great here.
3-I don't think this one works at all--it looks lazily taken without thought about the background, about their positioning; and the power in the shot, if there is any, is reserved to a tiny portion where their hands meet. Pushing in a lot closer would have made a far better image in my opinion. This feels like a pull-back shot for documenting purposes of the photo you intended to take.
4-Your exposure choice and focal plane placement urges us to take the couple as the subjects of the photo. The problem is that most of us will find the landscape more interesting than the backs of people's heads. When our eye goes to that cityscape and finds it is OOF and overexposed a smidge--well, it's unexpected. I'd have preferred the shot had the background been in focus and the couple allowed to be presented a stop 'underexposed' for the benefit of the background.