I'm really glad to hear that, and I wish you all the best with it!!
Oh wow. I congratulate you heartily on making it through! Even just doing the novels felt like it took fifty years off my life haha.
It's interesting which flaws stood out to you! Especially Roxas' character... as a huuuge Roxas fan, I always knew that my feelings about that would be biased. It's good to know you thought he was just as idiotic! And I also agree that Xion wasn't as bad in the beginning. I think it's because in the beginning, there was still a few plots that didn't revolve around her, namely Roxas himself feeling the effects of what Namine was doing to Sora at CO, and Axel having left for CO. But I think once Axel comes back from CO it's the start of the Black Hole of Xion Arcs and everything goes downhill from there. Well, that's what I think anyway!
And YES I've said all along, it's the weird lazy characterisations they gave Luxord and Demyx that's the insult. As the game stands, they do have definable traits etc, but instead of giving them depth or relevance it was just 'Luxord will make gambling puns and Demyx is lazy!' and they left it at that, cardboard cutouts of characters. But even despite that, Luxord was the highlight of the entire game for my brother, he would get so excited whenever he and Luxord had missions together haha.
I also hate the zip slasher ;__; I couldn't beat it... had to get my brother to do it hahaha