You have done a very good job of comparing the strengths and weakness of these offerings, but your account has demonstrated one of the problems with trying to pin Linux down: There is such a range of choices it's all but impossible to keep track of them.
Specifically, I'd draw your attention to Tasty Menu, a Kmenu alternative of substantial merit. It can be found on the KDE site. Another product worth mention is Mythbuntu, a Ubuntu variant which eases creating a K/Ubuntu installation with MythTV enabled. »
Encouraging a mono-culture has prices to pay as well. A better alternative may lie in strenuously encouraging all browser developers to support published standards, as well as established conventions. »