Your impressive knowledge of SW Airlines notwithstanding, you missed the point entirely. Mainly, how could an airline based in St. Louis, with 30 aircraft made up of 737s and Saab 2000s, with no international flights, with no flights even reaching the West Coast, possibly be considered anything other than a regional airline?
Well, I wasn't addressing the status of your airline, just your statement regarding Southwest. But, really, you used your statement on the position of Southwest as incorrectly being "Regional" as the qualifier for your own standing.
But, to address the point more specifically, I did tell you how your airline could "possibly be considered anything other than a Regional airline" -- it's based on the equipment you fly. If your airline primarily operates aircraft of more than 100 seats (i.e. 737s) on regularly scheduled service, it would not qualify as a "Regional" carrier by the FAA, but rather a "National" or "Major" carrier (dependent on the revenue). Geography of the flights is not a qualifier of the definition -- you can fly 747s on a 500-mile radius and you wouldn't be a "regional" carrier. You'd be a "Major" carrier if you made over $1B doing it, and a "National" carrier if you made less than that -- regardless of whether you covered more than a few states or not. If your airline was predominantly Saabs with a couple 737s thrown in then the FAA would likely consider it "Regional".