Launching a project creates a copy of the survey including all its elements like the survey questions and content, Rating Scales, Answer Lists and Question Themes. Editing them will not change the survey in a project once it has been launched. 

However, editing a Rating Scale, Answer list or Theme will affect the survey templates that use them. 

When deleting a Rating Scale, Answer List or Question Theme that has been used in a survey template, there will be a warning message with an option to assign another scale, list or theme. These items cannot be deleted without assigning another item or changing the survey templates in which the they are used.