All the photos should be stored in a DCIM directory on the phone. You should be able to see this directory and the contents from the File Manager program on a PC. Everything else on the iPhone is hidden away, but the photo directory should be visible.
Use the PC file manager to edit, delete or whatever with the photos.
Turn off the automatic syncronisation option in iTunes for photos and music if you want to manually control what gets backed up and copied across between the PC and iPhone.