There actually is a Bar named Big Dicks Halfway inn(Bar) at the Lake of the Ozarks in Missouri.
When Mustache Man hands Ken Scarborough a warning card, and every time he appears in the series, the piano music accompanying the scene is Jazz Suite, Waltz 2 (1924) from Stanley Kubrick's Eyes Wide Shut (1999).
The story of the "Pentaverate" was first mentioned in the 1993 Mike Myers film "So I Married an Axe Murderer". In this film the protagonists father is an outspoken conspiracy theorist and talks about the lore of the Pentaverate, including their role in world politics/ events and their meetings at "The Meadows".
The logo that appears behind Rob Lowe when he is explaining the Pentaverate is the ATV (Associated Television) logo from the late 1950's UK.