The General tab of SlingSync Preferences offers settings for file handling.

• Transfer Options
  Normally SlingSync asks you where you'd like your A/V files to be transferred (or converted then transferred). If you'd rather have your files always placed in a particular location, select the box, then specify the default location that you'd like to use.
  
• Other Options
  Normally, when there are still files in the Activity Monitor (meaning that there are still files to be converted or copied) then SlingSync asks you to confirm before you exit (quit) the application. If you prefer not to be asked, select the box.