"The use of the name would offer more protection than a foreign trademark."
I agree.
"My question would be, does the name have to be used for commerce or will any fair use site work as long as no reference is made to a would be complainant?"
It depends on the name. It is hard to conceive of a use for, say, "Kodak", since the term has no meaning other than as a reference to the company known by that mark. A word like "Camel", on the other hand, certainly has a meaning apart from a brand of cigarettes.
"How long would the site need to be in use to establish common law trademark status and again would it need to be a commerce site?"
Using a domain name simply as an address for a site is not a *trademark* usage of the domain name. For some background on that issue, you might consider the distinction between use as an "address" and use as a "trademark", which is discusssed here:
http://www.uspto.gov/web/offices/tac/notices/guide299.htm