I've been stoped by Corsairs, Outcasts, Mollys, Golden Crysth, and various rogue pirates. The most I was ever taxed has been 1 million credits.
Your taxes are way too high. 1.5 mil, then 2 million, then raising it each time the trader passes your way is unreal. Then I saw you tax a billionaire, which didn't even make sense as far as Role Playing goes (Would you ever rob Bill Gates?).
I suppose that sort of thing will get you what you want: nobody will trade through Kusari while you're there. But then you'll get minimum RP interaction and taxes. And if that's what you want, congradulations. I just think it's brutal to a point where it ruins the fun for most trades. And no, I'm not the only one who feels this way.