Just wanted to update how I addressed the problem.
Thanks to Matt for pointing the CSS fix.
CSS is only styling the extra character inserted after the menu item, indicating the submenu is present. Disabling the CSS only removes the 'down arrow' styling for that character.
To remove the submenu indicator completely, this needs to be done in the superfish.js file located in the following file.
\blocks\superfish\js\superfish.js
Line 18 looks like this.
$arrow = $(['<span class="',c.arrowClass,'"> »</span>'].join('')),
Change this to (change the html part to non blank space.
$arrow = $([' '].join('')),
Works perfectly, no issues with the rest of the menu.