Re: tl;dr 2 of 2
I'd say "They haven't proven themselves to be violenetly insane" but Bruce has had his moments and Tim isn't looking to good at the moment.
Generally, when I see a heroic character following an negative or even villainous leader, my brain usually jostles between "Something's up in that relationship" or "That hero must be a goddamn idiot."
The later only occurs when the former does not (though I bet there are other alternatives that I haven't thought of ATM).
I'd rather see a character filter orders through their own morality than mindlessly follow. Especially from a flawed source. One of my favorite films, Ran does a great job with that when a Samurai is ordered to kill and bring back the head of a young Buddhist nun the Daimyo's wife feels is a threat to her (because she's evil). He instead says he did it but brings back the severed head of a Fox Statue and says "She must have been a Kitsune who tricked me!". The cultural background gives it levels of awesome.