Great Report.
Yes, the SQ Lounge at SYD is nothing to write home about. I had a similar experience trying to gain access to the MLL, as you did at SYD with SQ, at LAX- it really wasn't worth the bother in the end.
Have begun to hear to hear some great stories about the service on UA on the Aussie flights.
Annie is a legend.
I never knew they served Hot Dogs in the lounge, though I am ususally there in the mornings.