I often use Multitrack to edit a single audio source file on a single track (Track 1) since Multitrack is non-destructive.
When I create a new Multitrack, it has many tracks, but I only need one. Premiere Pro has a Delete Tracks menu item. Please add it to Audition. It would also be helpful to have in the Preferences>Multitracks a field which specifies how many tracks to create for new Multitracks. Thanks
You can already Delete tracks from the Multitrack menu Track/Delete Selected Track.
That's what templates are for. When you click on New in Multitrack view there is a box for selecting various Multitrack layouts, including a single Stereo Track session, in the pop up New Session pane. You can also save your own templates. Once you have set up a Multitrack session as required go to File/Export/Session as Template.