> There is no equivalent to rebuilding the desktop.


Well...

• First, there still is the old version... available in System Preferences --> Classic --> Advanced. (I don't claim that will help OSX behave better... but it wouldn't surprise me either).
   
• Second, there is a rough OSX equivalent. It would entail deleting various files (in Panther: /Library/Caches/com.apple.LaunchServices.6B.csstore and /Users/shortname/Library/Preferences/com.apple.LaunchServices.plist), restarting [perhaps]... and then running the sudo update_prebinding -root / command in Terminal. [Though -- upon restart -- I'd expect the OS would probably do this on its own... once it notices the missing cache file.]

The prebinding mechanism has apparently evolved with different OSX versions (and I don't pretend to understand it totally... but I not convinced it has been perfected in Panther either). I'm starting to believe that over half the strange symptoms reported here at MacFixIt could be cured with a permissions repair, followed by the "desktop rebuild" procedure above (both of which are simplified by utilities such as Cocktail, etc.).

-HI-