Usually versions below 1.0 mean incomplete and from 1.0 on mean complete, true, but there are exceptions in both directions. Generally a version number is only important to the dev and you only know that a higher version number of the same game means a more recent version. There is no way knowing how much the story advanced or similar. And yes, this game is far from complete, it merely started.
Not at all. It also has a very different style of gameplay. So apart from the main characters both being teachers, the games have nothing much in common.