Once mine are changed, I will never be able to get them back.
They just are but you can stop it by changing your settings
You cannot. For a game to work properly, it must have a path from the server to the client program running on your computer. You can configure your computer to be wide open without changing the router settings, but if the router is blocking the port(s) you need, there's no way to get around it without adjusting the router settings.
File>Save Game as Runtime
i do not have the game, but if you go to options or settings and your save file, just delete the saved file and you can restart all over
Save it as a .exe file. (To do that go to the file menu and click save as executable)
It does but you have to create a save file after you open the game
Not without an emulator and downloading the game disc into a file
Most Linux applications store files somewhere int he user's home directory, either in a folder of their own (such as .applicationname) or as a single configuration file. Deleting the configuration file should return the game to the default settings. Alternatively, you can try modifying the settings file and fixing the bad resolution manually.
You don't without changing the game to add them in
To do this for sure, go to system settings and then to storage, find your game, go into it's folder and you will see a few files. One of them is a "Save data" file, delete all but this.
the only way i know is to delete the entire game save file which will also remove your multiplayer forge and spartan ops progress. its in system settings somewhere to do with game saves
You could have bought it in another country, or ordered it from a website that was foreign, which means that you would have to change the settings. You could probably do that by changing the settings from the main screen when you turn the DS on, or maybe on the settings for the game.