You started off this argument talking solely about how it glorified eye-for-an-eye retribution when it obviously and demonstrably didn't because the offenses weren't the same.
Eye for an eye retribution deals with damages, not offenses, even if you're willing to nitpick on the most literal of interpretations. Shield was humiliated and had his social standing ruined - his vengeance was the same.
You then slithered on to talk about the format of their justice system, also acting as if the writer not wasting time with citing the statute IDs
For someone accusing others of problems reading, you surely have issues following a simply presented argument: the parody of a court in which Shield agreed to participate legally allowed the queen (which was apparently supreme legal authority unconstrained even by traditional law the way she'd be even in real-life early Middle Ages) to issue any sentence and condemn anyone to anything, with no law or precedent limiting her options.
Yet, the result was what happened in the manga - on Shield's decision and thus on Shield's responsibility.
You claimed the magic slave crest was a mind control device, and then when it was demonstrated that it clearly didn't control its bearer's mind, you tried likening it to conventional torture.
Mind reading is mind control, pain delivered for acting "wrong" without damaging the body is mind control (and torture, yes). Do you think nitpicking adds anything to your arguments?
It apparently doesn't matter that Naofumi didn't even know it was applied before it was revealed.
I have nothing to add to "no difference whether it's at his order or as a result of his actions, with no protests forthcoming from him when he could present these" already stated above.
It doesn't even make any sense to think that someone who (also parenthetically provably) didn't want to do a double execution of her kin would force said kin to say things that would mount the case for their execution.
I am sure you can think of dozens of possible reasons to have a potential death sentence hanging over the heads of potential political rivals if you just think for a quarter minute.
Much easier to imagine than a reason for anyone decent to participate in that kind of a show trial, much less invent novel and particularly humiliating punishments for these who'd wronged him.