Outlook and IMAP - Outlook doesn't allow the Drafts and Trash folders to sync with the respective IMAP folders
Solution 1:
Slight correction, you can change the Trash/Deleted folder as well, indicated by the screenshot below. The only folders you can't remap is the Drafts and Junk Mail folders.
As for the rest of the question:
No
There is no workaround. I have found this frustrating myself and the same behavior exists in Office 2011 for the Mac. There was a workaround for 2003 but it fails in 2007 and higher.
As for why, any reasons except an official response from Microsoft would be purely speculative. I am guessing it is due to the way office rules are linked to the folder locations.
Solution 2:
A possible work around would be to impliment a rule or macro to copy the contents of your outlook data file draft folder to the imap draft folder.
Having said this, I cannot find a rule that acts on messages within a folder. Does anyone know how to do this?
(PS I would really prefer to have enterred this as a comment, not an answer, but I don't have enough points for this. It would be great to get bumped up a little. Thanks.)