When safe mode is on
chown -R your_user:apache_group * (except for temp/ and storage/)

For the openbasedir
Bw opens :
/tmp - need to be in the open_basedir
/proc/loadavg - if not in your open_basedir, no load statistics will be produced
/proc/stat - the adodb stat ... not sure what happens if not in the open_basedir
/var/tmp/file.tar.gz - mail attachment... not sure what happens if not
....
the session_path doesn't need to be in your open_basedir (But be sure it is a directory and not a file - the control will not be done)

Tip: open_basedir syntax for more than a directoy
php_admin_value open_basedir "/tmp:/my_local_to_bw"