What so your a criminal and a thief?
Law of the Wasteland: Guy with the gun makes the law
Besides, I'd open up TP to traders and make a visitors floor, maybe a refugee quarters like in Vault City and it's Courtyard, except I wouldnt charge people in the refugee camp 'protection' fees. Plus, I'm a pragmatic man, killing one evil man for (what I deem) the greater good, I feel it would prove beneficial, what did Tenpenny do? He lived as a recluse who absorbed all caps, with little trade with the outside world. I'd welcome all traders, permitted they hand over their weapons during their stay, or their ammo if the guns are for trade. I'd recruit men and train them to use power armor, then use them as the exterior defense force, combat armor men for inner security.
Way I see it, if you work with Tenpenny, you're likely going to do a criminal act, might as well do the act that's a favor to the world
@CNC- I wouldnt really rely on ingame details. I'd go by lore descriptions.