Is there anything stored in any PE-generated folders that is NOT re-created if it is deleted? In other words, if I create a DVD project complete with menus etc. and keep the original video clips, the prel file and any stills generated or used, can I delete everything else including any/all PE-created folders? So far, my experience says YES but I'm wondering if that deletes anything esoteric that I haven't run into yet and that won't get re-created the next time the project is opened.
Correct. I am proposing deleting everything that PE generated. File assets (stills, videos and audio) would be retained.
I have re-organized my drive so the video, audio and still assets (ie., all my input data) are stored in a folder separate from the project files. Since PE is set to store everything it creates in the project folder, it is easy to simply delete everything except the prel file.