The password protected message you are getting for the comments is part of your comments.php template. You can get rid of that by making some changes to that.
As for aligning form elements, with the thousands of themes available, there is no one size fits all solution. That is why the form styles are fully customizable - but you are going to have to do some work on your end to customize it to your theme.
The link @mbrsolution listed has information on all of the different methods of customizing the forms (http://rocketgeek.com/plugins/wp-members/users-guide/customizing-forms/).
I would suggest working on a custom stylesheet, with the kubrick one as your starting point. You seem to have a content area that is not as wide as needed in the styles. If you build a custom stylesheet, you can work from the original as the framework and adjust the width of the various elements to take up less space.