... I would say that if you REALLY want to be greek bad enough, then do try for informal rush...and this time give ALL the sororities a fair chance....while I know that there can be some prejudgements made by the sororities simply because of your year in school or maybe even something else, but from the rush threads I recall reading -- yours included -- the rushees also make prejudgements about where they think they should go -- WPISweetie's rush thread is about to close but if you take a moment and read it all the way thru. you will see the transformation she underwent during her rush...admittedly her school seems to have one of the LONGEST rushes on record (and that can be a good thing I guess) but she really did try to do her best with keeping an open mind, and she did!
So all I can say is to YES try informal recruitment and if you will be around longer, you can find a way to work that unobtrusively into the conversation...but really really really give ALL the sororities who do informal rush a fair shake -- (check out WPISweetie's thought process around the time she got her bid and signed her pref card...) GOOD lUCK! and keep us all posted!
P.S. I rushed as a junior -- not even a transfer student either -- at Southern Cal -- so it CAN be done!!