This is getting funny (and out of hand LOL). Imagine this: you have a huge projects and in that project you have added lots of effects that are NOT used anymore on any track and lots of soft synths that are NOT used anymore on any track. To prevent stuff from loading and cluttering up the project you would like to remove all unused effects and soft synths. But because you completely lost track of what's used and what's not, it would be very convenient if Sonar had an option that would scan the project for unused stuff and then remove it. And my question is: is there such an option? Apparently not...
Copying all the tracks to a new project: then you lose all connections to the soft synths, I guess? And will effects be copied too...?
Well, I think the only solution is to check each and every track for what it uses and what it is connected to and then manually remove unused items...
EDIT
P.S. Forgot to explain 'remove safely': InDesign is a lay out program, brother (sister?) of Photoshop and Illustrator. When I want to remove a color from the list of colors I get a warning if the color is used by an object: I can choose to cancel or to replace the color with another color. Now when I want to remove a soft synth from a Sonar project I don't get a warning like that: if a track is using the synth or not: you don't know... So if is not safe to simply delete a synth because it might be used and something may go wrong due to that. It would have been great already if Sonar would warn me if I want to delete a synth that's being used!