Few notices.
1. In your install instruction there is written http://<yourdomain>/mibew/install but it's wrong. URL should be
http://<yourdomain>/mibew/install.php/install
2. I was installing it in http://<somedomain>/~<myusername>/mibew/
So according to your instructions it should be http://<somedomain>/~<myusername>/mibew/install and it's incorrect. Just not found error.
Plain http://<somedomain>/~<myusername>/mibew/install.php also does not work. Redirects to http://<somedomain>/~<myusername>/mibew/install.php/operator/login and white screen.
3. So the only URL that worked looked like http://<yourdomain>/mibew/install.php/install
Just regular users with little programming skills definitely won't ques this URL...
Goodluck