The Project Manager in Premiere Pro is designed to consolidate and trim source files.
By the sound of it, your main requirement is to remove conformed audio, previews, and some unused clips.
You can simply delete the folders containing preview and conformed audio files for your project to get rid of those.
To remove complete individual clips that you haven't used, sort the project clips on the video/audio usage fields to collect up the unused clips, highlight the unused, then use the menu option to unlink clips, which will offer you an option to delete source files.
Use the Project Manager to transfer the project to another location with trimming to reduce overheads in used clips. When relocated, test the new project before removing the original.
If you have several project files using one set of source files, then you would need to be very careful with both manual and Project Manager activities that delete source files, or you could adversely affect another project using different segments of the same source files.