How to move large amount of objects (including BP) at once?

You could attach the entire spaceship interior to some kind of parent object (possibly the spaceship itself?) and then only move that one. To do so

  1. select your group of objects
  2. right-click and choose Attach To
  3. select your desired parent object

Once they’re properly attached (displayed as child objects in the World Outliner), you’ll only need to call all your movement/rotation functionality on the parent object.