3.1.2) I play a game with no time control and my opponent stopped moving, so it seems that the game will never finish. What can I do now?

If it is really clear that your opponent will not play the game anymore (for instance, he stopped logging in BrainKing 2 months ago), please send a message to the administrators and the game will be deleted. However, it is recommended to think twice before accepting a game invitation with no time limit and that's why a warning in bold red letters is displayed at the game invitation page, so you always play such a game at your own risk.