You notice that I said "Renamed". If you rename your Inbox, in the old profile, to, let's say, Oldinbox and copy it, and then Paste it into the account folder of the new Profile, then you will have a separate folder. If you don't, you will overwrite the Inbox, and have no current mail. And, of course, you have to know where is the default location of the profiles, which are not as expected:
http://home.att.net/~cherokee67/ns7profloc.html
I have heard of people furiously working with the 4.x User profiles, messing it up, if 4.x was installed. And, you use Windows Explorer, not Outlook.
As for the popus, I don't know if you can make exception to certain sites. But, you can in NS7.1. And, of course, they give you some twenty exception which you don't want. But, they can be removed.
UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax) (CK-SillyDog)