I agree with Khev that the most cringe-worthy moment was the CG Leia. One of the problems is that the film ends on that note. And so, forget the story as a whole, the way you begin and end are going to stick with people. Walking out of the theater, that is what sticks in my head despite a lot of the other stuff that was good. And that taints it to some extent. Seemed unnecessary. Downey, Jr. was done so well in Civil War, and these are both Disney movies, so I don't know why it didn't work as well here. But. . .it didn't.
Another thing that I thought would be kind of cringe-worthy, but surprisingly wasn't was Ghost Dog. He had the potential to ham it up in a Predators/Lawrence Fishburne kind of way, as the grizzled old nutcase, who somehow survived hiding from the bad guys for countless years because he was so nutty. But, I think he pulled his role off very well.
On a related note, I remember seeing him with close cropped hair in the trailer. Did he have that in the beginning of the movie? Or was a change made with the reshoots maybe? I was thinking about that in the theater.