Thanks for the response! I'm sure I sound like a raving lunatic by now, but I'm halfway through wasting a second day of coding trying to figure this out...
OK good call on the semicolons, I could have sworn it was throwing errors on missing semicolons before I was having these issues though. OK i just figured out some weirdness, I removed the '>' from the end of my ADG declaration (mxml), and it won't throw an error in source mode, but as soon as I switched to design it knew there was a problem and on what line it was on. Weirdness... Here's one I would think should cause an error: var x:int = 'a string'; No go though...