You can see from the log that the problem seems to be related to the MercurialEclipse plugin. I'm not sure if the original freezing is also caused by MercurialEclipse, but I wouldn't be surprised.
Side note: Mac OS X doesn't make it easy to access files starting with a dot, in a directory whose name starts with a dot. You can't really do it with the Finder (AFAIK). You can't even do it with an editor since the standard open file dialog also hides them. I usually just open a terminal window and cat /Users/andrew/workspace/.metadata/.log (On the positive side, you can copy the path from the error pop up and paste it into the terminal window.)
The solution I've come up with is:
- go into your Eclipse/plugins directory
- rename com.vectrace.MercurialEclipse_<version>.jar to ...jarX (i.e. add X on the end)
- start Eclipse (it should work now, but you won't have Mercurial)
- quit from Eclipse
- rename the file back (remove the X from the end)