Renaming wp-admin to /

I’d like to use the dashboard as the site, so when someone visits the example.com they are automatically taken to the dashboard.

I’ve got this part working by simply setting index.php as:

header( 'Location: ' . get_bloginfo('url') . '/wp-admin' ) ;
die();

However, I’d like to hide the /wp-admin bit altogether. So they only see example.com/, or example.com/edit.php instead of example.com/wp-admin/edit.php

I also tried adding an admin_filter:

add_filter('admin_url', 'backend_only');
function backend_only(){
    return get_bloginfo('url') . '/';
}

Finally, I would like to mask the .php, so example.com/edit.php is actually shown as example.com/edit

I am very green when it comes to the .htaccess and I just keep putting myself in an infinite loop when I try.

Any suggestions?