Not at all. Take a look at this simplistic diagram:
legal institutions of Roman Republic (before 1st century BC) <------> legal institutions of Roman Empire (before 5th century AD)
legal institutions of Roman Empire (before 5th century AD) <-----------> legal institutions of Eastern Roman Empire
legal institutions of Eastern Roman Empire (before 11th century AD) <----------------> legal institutions of medieval Eastern Roman Empire
legal institutions of Eastern Roman Empire (after 11th century AD) <-------------------------------> legal institutions of Imperium Romanum after Sunset Invasion (16th century AD)
Assassination of
megas droungarios is comparable to assassination of, say, Secretary of State in USA and would be treated as an act of terrorism. Let me remind you that USA uses unlawful abductions, drone strikes, detention with no right to appeal and inhuman and degrading torture including waterboarding, sleep deprivation, beating and rectal feeding, not to mention several cases in which the deteiness were allegedly raped. And this is a modern democratic country with Bill of Rights, rule of law and all that Enlightment-related stuff - which didn't stop it from breaking United Nations Convention against Torture and virtually all human rights.
So to reply to your list of "rights":
If anything imperial dungeons are less horrifying than Guantanamo or Abu Ghraib because the
Athanatoi don't have the knowledge of physiology, psychology and anatomy we have today, not to mention technical capabilities.