Let's try and make this pretty simple, then, and use as a starting point a quote from
North American Medical Corp. v. Axiom Worldwide, 522 F. 3d 1211 (CA5, 2008):
We conclude that the plain meaning of the
statutory language clearly indicates that Axiom’s use of NAM’s trademarks as
meta tags constitutes a “use in commerce . . . in connection with the sale . . . or
advertising of any goods” under the facts of this case.
Now, one of your proposals (if I understand correctly) is using a meta tag in order to manipulate the search results, which in the cited case, at least, was held to be a "use in commerce", and the question then would be whether the use could cause confusion in the marketplace, or else dilute a famous mark somehow. You're also proposing to use the universal resource locator address of the web page to hopefully achieve the same result. I do not believe that a court would find there to be any difference between your proposed use of a URL and the use of meta tags.
In addition, the court in
Brookfield Communications v. West Coast Entertainment, 174 F.3d 1036 (CA9, 1999) found that such a use might cause 'initial interest confusion':
Nevertheless, West Coast's use of "moviebuff.com" in metatags will still result in what is known as initial interest confusion. Web surfers looking for Brookfield's "MovieBuff" products who are taken by a search engine to "westcoastvideo.com" will find a database similar enough to "MovieBuff" such that a sizeable number of consumers who were originally looking for Brookfield's product will simply decide to utilize West Coast's offerings instead. Although there is no source confusion in the sense that consumers know they are patronizing West Coast rather than Brookfield, there is nevertheless initial interest confusion in the sense that, by using "moviebuff.com" or "MovieBuff" to divert people looking for "MovieBuff" to its web site, West Coast improperly benefits from the goodwill that Brookfield developed in its mark.
And I have found allusion to cases in which use of meta tags has been held to constitute dilution, as well, although I haven't had the chance to dig through and find any especially-quotable cases.
The lowdown for you is that your use of a URL or meta tags which contain a famous mark could very well be trademark infringement. And the basic rule is that you can be liable for damages for trademark infringement the instant that the infringement happens, which means that Coca Cola or KFC or whoever's mark you used wouldn't even necessarily have to send a nice cease & desist letter (although they might) -- they could just hit you with a lawsuit that they'd have a decent chance of winning, and then you'd potentially be on the hook for quite a bit of money.
I hope this answers your question as thoroughly as you would like, with as little room for equivocation as you'd prefer.