Secure use of Contact 7 and WpDataTables for sensitive data in WordPress

I am considering using Contact Form 7 and WpDataTables in order to collect and display sensitive data in WordPress. I will be using WordFence as an all-in-one security plugin. I will also be sure that all inputs are sanitized and validated via JavaScript and PHP. Data in the multi-form process will be updated via an AJAX post request after each form. These too will be validated and sanitized.

Is there anything I am missing, especially in regards to using AJAX?

Does anyone have any security suggestions above and beyond what I have listed above?

Thanks in advance,

Marcus