To unlock 5 and 6 nsfw page on tate`s route you must go on oliver`s route. don`t go on an adventure with tate and then go on date with oliver and merina. Make all the choices in favor of Oliver and then he will invite you to his office in the evening and you will need to go to him. and about second question, yeah, all pictures in gallery obtainable, i already have every picture so i happy to help)))