Not just LIs but for any characters, I don't like a character who basically can't solve any problems and just panic and do things that make everything worse. Another one is someone who doesn't listen. I know sometimes they do that to make the story more dramatic, but please, just shut up for a...
I always keep the default name if the game has voice recordings for it. I want to enjoy the voice actors' performances as much as I can, including the way they call the MC's name. It doesn't bother me that it's not my name, I just enjoy being someone else in the game anyway.