Obviously, your knowledge of pre deregulation era US aviation law is limited. Further, it appears that limited range extends to your insight on Pan Am's competitors..i.e. Northwest Airlines, TWA, Braniff, AOA.
"grandiose"?
(That seems an understatement..)
Pan Am owned its famous New York Building at 200 Park Avenue (built as the largest office building in the world), the Inter-Continental Hotel chain, Pan Am World Services (that conducted launches at Cape Canaveral), the insurance company, a 50 percent stake in Falcon Jet (the private executive jet builder), the Atlantic Division, the Pacific Division, the Latin American Division, Pan Africa, the Internal German Services (Pan Am was the only U.S. airline to fly the IGS with Lufthansa between a divided East and West Germany during the existence of the Berlin Wall), and later the East Coast Shuttle (flown between New York-Boston-and Washington's "power corridor"), Pan Am Express (the commuter airline feeder).
I think it is more than qualified at being referred to as "Grand".
I'm very familiar with pre-dereg law and Pan Am could have had domestic services if they had really aggressively gone after it. Pan Am just wasn't interested (until it was too late) because they wanted the international market.
While Pan Am had quite a list of products, many of them actually distracted the company from its primary mission. Taking your focus off your core business is usually a mistake. I guess that's one thing you can credit Pan Am for teaching the other airlines.
Delta and United don't owe anything to Pan Am for their existence. Long before Pan Am died, UA and DL were on their way up. Even if Pan Am was alive today, UA and DL would also exist and have extensive international route structures. Keep in mind that DL dumped most of the routes that Pan Am flew as most were losers. DL's strongest and largest international hub is ATL which would still exist even with Pan Am.