Hi,
It seems you didn't provide a link to the page you're talking about. Could you provide that so that we could directly look at the problem and analyze it ?
If you want to change the way the system works to load comments in AJAX, it sure is possible but will require some heavy code change. You'll need to have a developer to work on that. Note that we spent almost 2 years on HikaShop 3.0.0's new checkout and new cart systems as we had to almost start from scratch. It might look similar to what was before, but that was done for backward compatibility. The system behind is totally different in order to accomodate the AJAX system (dynamic refresh) properly.