Display breadcrumb
Sometimes you may not want a breadcrumb displayed at all anywhere on your site. If that's the case, simply uncheck this box and no breadcrumb will be displayed.
Breadcrumb separator
This allows you to customize what is displayed in between each breadcrumb item. An example of what you can choose to display in between might be a heart symbol, in which case you could enter ♥ into the box and the result would be each item in the breadcrumb area being separated by a ♥ symbol. NOTE: if you don't surround ♥ with a space on both sides, there will be no spaces in between the separators and the breadcrumb items (so in most cases you'll probably want to put a space on both sides of ♥). You could also enter  ♥  without the surrounding spaces and achieve the same results. Another possibility would be to enter  ♥  which would produce the exact same output as  ♥  would.
You can also enter something like <span class="custom-breadcrumb"></span> -- this is especially useful if you tell the theme to scan for custom stylesheets (explained in the custom stylesheets section).