iPhoto Library and Original files

I am wanting to clean up my photo files (14000+) and have been using iPhoto since I bought my iMac this spring. The only thing I am concerned about with tearing it down and starting over is what iPhoto does with the files in it's "Originals" folder.
Anyone have any help for this?

What do you mean? iPhoto is non-destructive, so anything in the Originals directory are well.. the untouched originals.

Besides, you are not supposed to go mucking about in the iPhoto library in finder. Messing with your photos in there will lead to major headaches. iPhoto will not be able to find the photos for you. Stay out! If you want to delete photos, do it from within the app itself. Then iPhoto will continue to work for you. Do anything and everything to/with your photos from within the app itself.