I was experimenting with restricting multi-user linux boxes.
A few days later trying to run QCAD with the above security settings threw this error:
QInotifyFileSystemWatcherEngine::addPaths: inotify_add_watch failed: Permission denied
QCAD froze.
I had to go back to 755 on /home to allow QCAD to show the file chooser dialog (e.g. when you select File ==> export bitmap)
Looks as though the QT app requires world readable to work.
So stopping people listing the /home directory may only be a workable solution on a shell access only box.
I ran into this exact same issue with Amarok just this morning. I'm guessing the QT class having trouble is trying to walk the directory path entry by entry from root. For the record, 711 on /home and 711 on /home/me resulted in similar problems. I'm thinking this is a bug in QT personally, since as long as you can access the end element of a path, why would you even care what the top-level perms are?