"Someone" has apparently tried to comment out things like navMain and the breadcrumbs on the main page.
First of all, breadcrumbs are controlled in the admin menus.
divs can be set to display: none; in the CSS.
Using <!-- commenting out --> can often be confusing in a php-generated html. As happened on your main page, a beginning <!-- or ending --> is often forgotten or dropped.
Also, if a <br class="clearBoth" /> is in a file, I would think four times before commenting it out. Shifting errors in browsers are often the result of some setting "hanging on" longer than it should.
Trust what's there, add what you need, test often.
I don't know if premium has any connection with TM, but they look like they're at least trying to follow in their footsteps
