Format->Text->Show Ruler (or cmd-R) ought to give you some of the tools you need to get the mess cleaned up. But to clean up the hard wraps inserted in the text, you need something like WordService:
http://www.devon-technologies.com/pr.../services.html
There's a good thread on this general matter here:
http://forums.omnigroup.com/showthread.php?t=10591