I'm not a wedding photographer, but I've been to enough weddings, and shot enough (both young and old) to say that I'd be pretty happy to have shot these. Under the circumstances, there's usually very little time to work out the technicalities, and you go with what seems to work. Swettylens may have valid points, but it's always easier to critique after the fact. I know in the weddings I've shot as a family member, each wedding is different, and I've had to adapt to the situation with the equipment I had with me. Usually takes a few tries before the images start coming out decent. But that's me. Your photography in the studio and the shows reveal a pretty good understanding of light. Here the difference was the on-camera flash.
(actually a Canon 430EX on the hotshoe, but in my hands, pretty much an on-camera flash, at least in the beginning) Perhaps in the ideal world they could be improved on, but we don't know the environment, so what you could have done differently is speculation on our part.
"The Groom" - technically, the flash is a bit too hot. Focus is good (maybe too good for this particular shot), and you've caught his eyes smiling and him looking happy.
Yes, direct flash. But yes, you get it. His eyes are smiling, and his whole face is smiling...he was happy and he was about to get married. The teeth don't matter.
"The Bride" - good exposure, but somewhat flat. She's happy. Focus is bang on. If you had some control over the posing, I'd have suggested a 45-degree bend to her body, with her looking at the camera with her head slightly extended and slightly tilted upwards - that would give a clean neckline.
No posing...she was heading into the registry office ceremony room. A grab shot, really...just liked her smiling.
"The registry office" - from the shadows, I can see that you bounced the light above and behind you. Good exposure, and good image under the conditions.
Yes, I tried, in a limited space.
"Best Man" - here I think the direct flash works very well, separating him from the background. The image looks tilted slightly to the left (tree in background, his posture). Cropping some from the right and a bit more from left (square format) could be considered. He has a slightly impish almost-smile on his face.
Again, direct flash could have been done better, I agree. But again, you see the swagger this lad had...he was a great character, and loved his mum a lot...he cried in the ceremony. 
"Small Group" - good lighting. Like the way the leaves above frame them. Looks like the flower girl had an accident earlier, but participated anyway - a trooper! Groom looks like his eyes are closed, but I know people like him who always have their eyes almost always mostly closed, and it is difficult to get them to open wider.
That's how he did his eyes all the time (almost). The little girl had her leg straightened iin an operation a couple of weeks before. She was my shadow, even took a couple of shots with my camera herself.
"The couple" - good lighting, separation from background. In terms of posing, I'd have asked them to rotate their bodies inwards a bit, towards each other. The groom seems slightly shorter than the bride, and perhaps shooting a bit more to his left, and from shoulder level (not eye level) would have made the two more equal in height.
Yes, I see how that would help. Thanks.
Overall, I think you did very well, and contributed to the occasion. I'm sure they will be very happy with the images they get from you. Contratulations.