Other than Wang Junxia, there are four women that have run sub 30. However I agree with most of the rest of your post. I don't expect to see Shalane run faster than Melkamu, Dibaba, Abeylegesse and Defar. Shalane ran 30:22 in a race where most of the top 10 ran their best ever times. The likelihood of finding herself in a similar race again is slim. The likelihood of her running sub 30:22 (let alone 29:45) at Daegu or anywhere else in 2011 is slim to non existent.
In the 5k there are more chances to run fast and if we look at Kim Smith who ran 14:39 indoors while lapping other runners, then we would have to assume that in ideal conditions, Kim could run 14:38 or better outdoors. Shalane could do the same, so 14:35 to 14:40 if she gets in the right race on the right day.