Hi (again) I learbed that scnenes could be loaded with the Application.LoadLevelAdditive("SceneNameGoesHere"); function.
Here is my quesition : In order to create a map generator, I must give scenes some properties (i.e. the theme of the scene, the possible connections, if it's a "side scene" or not ...)
So, is it possible to give properties then sort the scenes and randomly pick ones with some filters ?
Sound like you need a singleton to store a (list/array) of scenes and associated variables to refer to, if using pro just place a script with this scene related variables/info in a Plugins folder created in the project folder or if using indy see this link: http://www.unifycommunity.com/wiki/index.php?title=Singleton
Its possible to make a scene resiliant gameobject with attached script see "dontdestroyonload" function, the only issue you may have is when reloading scene 0, where you first placed the game object and script in the hierarchy, you may end up with two scripts doing the same thing, as a new one is reloaded in and the existing one is still present.
Load level additive is also ok if you want to keep things in scene, so you could create an empty scene with game controller/functions, scene loader and scene variables etc, application.loadleveladditive the scene requested and when finished with that level destroy the game objects of that scenelevel before loading another additively, in which case it would be wise to put all you scenelevel gameobjects and code under one parent gameobject called something like SCENE on each loadable level, so it easy to remove the scene data when loading another scene i.e. Destroy(GameObject.Find("SCENE");