2 tick boxes appearing below comments

Those are “subscribe” checkboxes. View source and you can see them and the rest of the content.

<p class="comment-subscription-form">
    <input type="checkbox" name="subscribe_comments" id="subscribe_comments" value="subscribe" style="width: auto; -moz-appearance: checkbox; -webkit-appearance: checkbox;" /> 
    <label class="subscribe-label" id="subscribe-label" for="subscribe_comments">Notify me of follow-up comments by email.</label></p>
<p class="comment-subscription-form">
    <input type="checkbox" name="subscribe_blog" id="subscribe_blog" value="subscribe" style="width: auto; -moz-appearance: checkbox; -webkit-appearance: checkbox;" /> 
    <label class="subscribe-label" id="subscribe-blog-label" for="subscribe_blog">Notify me of new posts by email.</label>
</p>

The text for the checkboxes is hidden because your stylesheet ( http://vikingsandc.co.uk/wp-content/themes/novatorix/css/firebrick.css ) has #commentform label {display:none}

I am not sure exactly how to remove them because it is a theme issue, mostly. Look in comments.php and look for comment_form. I think that is the most likely location for this code. There are several hooks in comment_form so your theme may be using one or more those to add the checkboxes. Maybe look for a callback to wp_list_comments as well.