Multiple comments / comment date

Hi there,

tested the guestbook on my testsite, but I wonder about the comment function:
As I figured out:
-comments can only be posted from authenticated users
-it can be posted only one comment or only one comment per user?
-the information of date and time is not posted for comments.

I find it really useful having multiple comments (also for anonymous users) in a guestbook like I did on my old site:
http://www.los-skalameros.de/guestbook/

How can this be achieved in drupal?
Maybe there is a module out there which can meet this requirements?
Any suggestions?
Thx.