To fix the error regarding names where character names change into NONE/[mil2] during the gallery , start a new game from scratch. Then when you reach the point where you have to determine the relationship of the characters, fill them up normally and then save the game in a different file. Next, load up your game and it should the names should be fixed.
Gallery not working is strange. Did you complete the events leading up to the gallery? Does it say LOCKED? What is the affection of the characters? Have you tried starting a new game to see if the scene is unlocked? This is an unusual bug.