Hey my iso file won't accept device files so I was wondering how I could mount a cdrw with an iso9660 filesystem as read write to copy device files to the cdrw.
You can't mount iso9660 read-write, the filesystem is laid out for reading only (there is no space for files to grow, for example). I don't know if you can create such a filesystem with device nodes either. What are you trying to do? If you want to create a custom LiveCD, look at the tools your favorite distribution uses to do that.