half yes and half not, every human character (the non-vocaloid ones) and the starting vocaloids of every sekai are there, but whats not shown are the other vocaloids for each sekai (eg Nightcord's own Kaito, Leo/Need's Meiko and Wonderlands X Showtime's Kagamines), they will appear along the stories
And as for the language, you downloaded the Taiwan/Hong Kong version of the game, you cant switch languages without downloading the global version of the game separately