1.You don't have to put it into your jed folder.
2. yes it could mess the level up by having several in the same folder.
3. make sure to hit F10 to check for errors. Also make sure there's a walkplayer in the level.
4. Are you sure your saving correctly?
5. Make sur eto check out my other tutorials in the jk forum.
I calculated the odds that this would work versus the odds that I was doing something incredibly stupid...and I went ahead anyway.