apple.local Dock[255]: ECFileOperationRevealURL failed with -43
I suspect that PathFinder isn't actually the culprit here.  I downloaded and extracted (although didn't install) PathFinder, and searched for ECFile, and found no matches:

Mitsu:Contents ashley$ pwd
/Users/ashley/Downloads/Path Finder.app/Contents
Mitsu:Contents ashley$ find . -type f -exec grep ECFile {} \;
Mitsu:Contents ashley$


I suspect ECFileOperationRevealURL is actually the name for some code within the Dock application itself.  I say that because I found the text ECFileOperation in a 2007 webpage where people are discussing features added to the Dock in a beta release of OS X 10.5.  I can't verify this easily on 10.8, though, as /System/Library/CoreServices/Dock.app/Contents/MacOS/Dock is now an apple-protected (encrypted) binary, which can't be meaningfully searched with grep as above.

So, some suggestions:


Just to check I have the right end of the stick: you are saying that if you cmd-click an icon in the Dock, nothing happens, except that you get an entry in console.log?
Is this true for both applications (to the left of the Dock separator line) and folders (to the right)?  (Assuming you have the Dock on the bottom of the screen.)
If you create a new user account (for testing only), does the problem persist there?
If the problem goes away in the new user account, try moving ~/Library/Preferences/com.apple.dock.plist to another location temporarily (say your Desktop), then restart.  This should reset your Dock setup.  If this fix doesn't work, you can always put the file back.  If it does work, I'd suggest setting up the Dock again from this fresh start.