A couple things...
If you bounced the clip gain adjustments, that will make additional files for undo. But I think part of the answer might be this: "until it crashes Sonar when it tries to draw the audio image."
Under Preferences > Audio > Configuration file, look for the entry for the PicCacheMB. I doubt the default is set up to handle the kind of project you're doing. Increase it, and see if that stops the crashing.
Next, create a new folder. Save As... to it, and check both "Copy All Audio with Project" and "Create One File Per Clip." See if that slims down the size.
If neither of these help, Save As... as a bundle file, then re-open it and re-save to a separate folder. Open the project and see if all is well or not.
As to support, sending crash reports will not necessarily trigger a response from support. I think the crash reports go to QA and dev, not support. Give support a call; by and large people on the forum give them pretty high grades for fixing things.
I also did some classical projects with very long files and didn't run into the problems you did, so hopefully it's something simple.