You just mentioned some excellent reasons, for me, to avoid Texas Gun Trader - especially the fact that you said you are definitely showing up armed. I never had to worry about doing a single transaction on Gun Broker while armed but I see folks repeatedly mention the fact they would never do a transaction with someone from Texas Gun Trader unless they were armed. That is apparently because so many crooks and scammers post sales there there and/or because of so many opportunists using that site looking for opportunities to rip off someone who is selling a gun.
I show up armed to every face to face transaction I do, including ones setup here. Of course I'm rarely in public without a gun on me and nobody is the wiser.