You can change the default queue settings as indicated, by clicking Edit > Queue A Settings... or by double clicking the folder showing "A".
You can also hide medias you don't use by shutting them off in the Media Explorer. Click Media > Media Explorer and click the "eye" on the left of the name you no longer want to see, and then OK when complete. This doesn't delete the media, just hides it from the list. If you only have one or two profiles that you always use... this comes in handy.