Please paste the output verbatim.
To test for your lacking execute permission, first find the metacity binary (I figure it would be /usr/bin/metacity; if not, try which, locate and find). Then do an `ls -l /path/to/metacity', and see if it says -rwxr-xr-x (and some more). If it's missing any x's, do chmod 755 /path/to/metacity. Try installing and running some other window managers (such as enlightenment, openbox, fluxbox, blackbox, windowmaker, olwm, lwm, twm, kwin, fvwm, ctwm, ion, ratpoison, aewm, 9wm, evilwm, icewm, jwm, wmii, ...). Do they work?
It sounds much like you don't have a window manager running. To fix that, find something like gnome session properties, and set your favorite window manager (still metacity after trying all the others?
) to run at startup. You probably also want to rerun it when it closes.
You may benefit from reading http://catb.org/~esr/faqs/smart-questions.html