Before I get into the other responses, respond to number 1 first. Why the hell did he not take out the other eye?

2) That was my point. It's an ACTUAL alternate world with monsters. You can't expect it to match video game tropes. I understand what you said that one must test assumptions, but my complaint was about his confidence. He COULDN'T be sure, but he acted as if he was. That was obviously for coolness factor. You may have done the same thing, but would you have been sure enough that it will work to bet your life on it?

3) That's the problem. It's an excuse that allows him to just pull whatever on us. I am personally sick of OP Gary Stus running around making stuff up as they trample their path across the new world. At least Tanya struggled a lot in her story. I think this is more of me being oversaturated with these wish fulfillment stories, which are a dime a dozen in light novels and manga, and now anime.

4) Did you just equate his lack of sensitivity towards death with manners? It's more of a moral question, and I'm fine with psychopaths who don't care about that. What I don't get is why he is the way he is. He was a relatively normal person, albeit very intelligent, in his previous life. He genuinely cares about his friends (which most psychopaths don't), but somehow, he is more concerned with the safety of machines over human life. Life over objects is not a perception limited to that fantasy world. It's also common sense in his original one, which is modeled after ours.

And yes, I would care, as would any logical human being. We aren't animals that only care about fulfilling our desires.