Once you have done your mix all you have to do is select all and while holding ctrl split all the tracks at the same spot. Then run the mouse over the time ruler to select the part you don't want and right click Edit/Delete. if for some reason you are not happy with that goto undo.
 
By the way even though you have deleted the portions of the track/s in the TV they are still there on disk if they are wave files.

I think you might be over complicating this. If you want a subset of the recordings in SONAR and don't want to backup the files I think you can do it all inside SONAR without any external apps.
 
- Import the original wave files choosing NOT to copy the wave files. This will reference the original files.
- trim the clips as desired in SONAR 
- select all the clips and choose apply trimming to keep only the trimmed data
- File save as and choose to save a bundle file. This will save a bundle of only the trimmed audio
- Reopen bundle to a new per project audio file and let it create a file per clip. You now have clean wave files for exactly what was trimmed
- delete the original source wave files once you are sure you have what you need