Some progress on flash, see notes.
May need to abandon flash as a messaging system. It appears that flash is used more to transport messages to the next page or action rather than display them instantly. So far, the experience with flash has been that an error 'flashed' on a submit doesn't display right away, but instead waits until the next submit (after the user may have even corrected the error. Flash might not be a better solution to the current setup.