Actually you should not compare Thief to COD or Assassins Creed ever. The original Thief had basically "created" the stealth genre. Expecting it to be anything more than a stealth/stealing game is therefore unrealistic. I am sure it would not appeal to those who don't like stealth games since stealth is a major portion of Thief's gameplay. If you don't use stealth, you won't last long. Also, you are a thief, not a murderer so no killing is justified. I haven't played it but from what I've observed there are no supernatural creatures like zombies, ghosts or burricks like the earlier thief games, so again there's no need to kill. Even earlier Thief games had limited health, so that is ok.
From what I've seen from review videos is that the lighting is great. Also, since the game is supposed to be dark, the texture quality does not matter at all. As for controls, it's mainly because this is a console port, therefore the console controls were mapped to Keyboard controls. That would explain the limited key bindings. But every arrow does have it's own key.