Is there anyway to remove old imports?

You've probably discovered that if you delete your old imports, the program crashes. If not, then deleting will possibly cause the prog to become unstable and crash. What i've discovered is that instead of loading in a new version of a part and then having to reposition it, you can select the old part (attached to the avatar), right click, and select "Re-Import Model". This will replace your current part with the new or updated one.

Yup, you can simply select them in the workspace window and hit the delete key.