We are sort of off topic but in a way that is why we are all saing we are going to stay with Sonar and that it will work for a long time.
OK I understand there are people who never finish projects. ANd this creates this problem. The danger of thinking you can take 10+ years to finish something when it comes to using a DAW as apposed to using a tape recorder. Things change and eventually your projects will be left in the dust.
So if you insist on never finishing songs then it's up to you to maintain the version of the DAW that they will play on. This is really only going to take you so far. So,,, before it happens -- finish it or at least re work it into a format that will stand the test of time.
Me becuase of the way I work my audio files are easily sorted out. I name them before I record. I also don't do comping or much punching in.
But if your audio folders are a mess you can do a few things to fix this.
Don't bother with clean audio folder , it seems to not work as expected.
Just use Save As and it will leave unused audio behind. You can also take a messy track with a hundered clips and bounce it to a nice new track and then delete the messy one. In other words you'll need to either finnish that song or do some work to make it future proof.
And for many a huge part of our work is midi. Midi is super easy to save,,, just use "save as" and choose Mid 1.
Oh you might what to assign different channels to each instrument.