I also thought of Amok Time! But why would they make that reference? And not do anything with it? Also agree on the Khionians, I didn't understand why they are all in their human forms. I also thought it was weird that everybody was pretty cool with a random Klingon to attend this important wedding.
I think this episode would have profited from being split in two. I know the 10 episode format only allows for so much episodes, but this one was a huge miss to me.
I don't know, they could have gone all in one the Khionian culture and his past and it might have worked. Instead we got a wedding I didn't care enough about. Likewise, the plot of "an empty school over the holidays" could have worked on its own. As I wrote somewhere else, with a show including Paul Giamatti, I was immediately reminded of the Holdovers. Two students and Reno, would have been a great setup I think. Instead, we got some hasty character "development".