Custom comment type maybe?

(First of all, sorry for bad english)

If there are people here using wordpress as cms, you probably realize that you dont need comment system that much. Esspecially custom post types like products need a contact form system that saves coming input.

What i am dreaming but cant coding:

Changing comment system for custom post types. Let me explain on an example:
Lets say we have a custom post type thats using for product list. We dont need/want customer comments on this product but we want customers send us what they are thinking on this product. So they will use this “custom comment type” system and sending us a comment but this comment is not publishing on website and in admin panel, when we reply to comment, wordpress will send that reply as e-mail.

So we can see all new contact form inputs about this product in a list as archieved in wordpress comment table and we can reply them from admin panel. When product is updated or a special discount or something, we will have a list of customers that previously asked a question about it so we can contact them again about new updates.

In background, as performance, product custom post type not need to load comments so this will reduce database queries.

What do you think about it? Possible?

I also (ab?)use comments for “private” replies to posts, like product inquiries, suggestions, answers to contests, … The advantage is that they are stored in the database and displayed in the interface without extra code from me (sometimes I add a filter to improve the formatting). Spam filtering and e-mail notifications are easy extras.

I think it is possible to create a custom comment type framework on top of the current system, thus as a plugin without internal changes. Maybe, if I ever find the time, I’ll experiment with that…