why would you put your main site in a subdirectory if you're just going to redirect to it anyway?
your php script looks fine, provided there's nothing (not even a blank line) before <?php. the file doesn't need execute permissions because it's going to be used as input to the php cgi handler -- my php file permissions are mostly 644 and are working. it's possible it won't work for some sort of security reasons until you remove execute permissions.
if those suggestions don't help, have a look at your log files, under ~/logs/example.com/http/ and see if there's anything there. error.log is probably your best bet -- request the web root directory and then see if there's anything new in that file.
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