Great job looks like your cousin and step family will be very happy to have memories captured which they will, im sure, cherish.
1. I like the sharpness of the subjects, and the background really makes them pop. I am not a huge fan of the blue/violets maybe tweak the white balance a little if you can or adjust the saturation of those hsl in lightroom.
2. Was this "the kiss?" Kudo on capturing this moment. The rule of 2/3 shouldnt be ignored here as it would have been a bit more appealing of a shot if the couple took up 2/3 of the screen. I do wish there were some background people also to show the story of it being the -till death- kiss. I think the pinkish color is a bit unnatural on this as well.
3. BAM! This shot puts the color in perspective. and what a great perspective! Just a great environmental portrait. Love the architecture, and i'm digging the color in this one, actually. Even though its the same color as the last 2 its working for me with this type of shot. Seeing the altar behind them tells more of that story.
4. This is a good environmental shot, and the same thing i said in 3 goes for this except less of a story.
5. Nice silhouette. It looks like you have cropped this down, I might have not cropped so close to the hands.
6. This has a movie feel to it, good rule of 2/3. I wish there were more fill light on the subject and less on the bright building in the background. Try to brighten up the skin a bit, bump up luminance on the red/orange, hopefully you can bring back some of that.
Indulge me if you will, how did you feel about going as a photographer, and not as a guest at your cousin's wedding?