You've identified a key issue with the ajax_comments module: it errors out when trying to "Add new comment" on a node with no existing comments because its JavaScript expects the comment form or section to already be on the page. Forcing "Show reply form on the same page as comments" fixes this by pre-rendering the form, but causes conflicts with modules yourtexasbenefits like Advanced Forum that expect the #comment-form ID. The ideal solution is for ajax_comments to dynamically load the comment form via AJAX when it's not present, making it more robust and eliminating the need for the workaround.