As an aside, RIO, you speak about these "friends" frequently. Why do you hang out with so many unrepentant cheaters IRL? I cant help but think that it's skewing your view of what's normal. With respect, and I hope you don't take this personally (I don't think you will), your friends sound like assholes.
I work with them, I have no choice. I avoid it as much as possible, but it's a requirement for my job that I socialize at least some with the people I work with. I now (post A) absolutely dread it, but it's how I make a living so.. It's just part of the suck of my job.
BTW, it's no better when you switch it around to WW who have grievances about their lack of emotional connection.
I understand it may be offensive to say/think that. But I quoted the above so that I could turn the lens to me and not generalize. I didn't provide the emotional connection that my wife sought. No sugar coating it, I just didn't. Did that mean she needed to have an A? Of course not. Could I have prevented it if I'd understood what she wanted and needed emotionally from me better and provided it? Yes, I'm pretty sure I could have/would have prevented it if I had done those things before. Now, before anyone gets all bent out of shape, this is NOT the case for everyone. I don't even know if it's even a little bit common, but it's the case for me. The A isn't my fault, but I certainly could have filled her needs better and, IMHO, it's likely the A wouldn't have happened. It's difficult to say that, even more difficult to think it, but, for me personally, I'm pretty sure it's true. It does NOT mean it's my fault, it does mean I could have done more to prevent it though. And I'll leave it there because I don't want to offend others.
And there we have it, an emotional rationale safe guarded by logical decisions that create incorrect outcomes. More than anyone, RIO, you need to discover your emotions. Despite what you may believe, they are doing more of the driving than you’d even care acknowledge.
That's possible. It just means I need to redouble my efforts to kill them off. 
And what about that outcome do you think it incorrect? I can tell you, it's not always incorrect, I've been taken advantage of by friends before. It's also not always correct, but it's not worth the effort to figure out. I just operate under the "he's my friend for the time being until I'm not longer useful to him" assumption. It's almost always proven to be true.
I think (better than most) understand that it's possible to like and/or love someone and not trust them.
I agree with this. Also, we have to define "friend" here. I think my definition of it is FAR more narrow than most here, especially with a statement like this which to me reads "yes, I like you, but you'll stab me in the back professionally the first chance you get". That's not a "real friend" to me. That's the guys I work with, I get along well with them, we have a lot of laughs together (or used to, pre-A). Would look forward to seeing them when we'd travel together. But I had absolutely no illusions that they wouldn't stab me with all their might the moment they saw any opportunity to climb the corporate ladder, or, if we were both pursuing the same woman, would stop at nothing to "win" over me. That's not what I consider a friend, it's what I consider someone who's company I enjoy(ed). So perhaps it's not different, it's just that a greatly narrow the definition of what friendship is to me. It's trust, it's caring, and it's not taking advantage of a situation for your own personal gain. And that's exceedingly rare, at least for me personally.
Here is something I’ve learnt from my Nerdy Trekky friends. They all aspire to be Spock. Like somehow a robotic state were we all drone on through our one dimensional utopia will free us from our suffering existence. But even poor Spock was half human and all you Trekkies weren’t even born with that level of grace. Nope, full human, how tragic.
Indeed, tragic. Here's the tragedy, I know I do have emotions. And if I let them to the front of my mind, I realize pretty quickly that I have 100 negative emotions for each positive one. They are a terrible burden; fear, uncertainty, doubt, working from an emotional basis with no grounding in facts or rationality.. It's an awful and terrifying place to go for me because it's just so overwhelmingly awful. So I turn it off, and yes, I do envy the "Spock character" (or really, more correctly Vulcan mentality) because they've controlled their emotions to the point where they no longer have any bearing on their decision making process. I wish I could be like that, and I aspire to be like that. Let me tell you, working from an "emotional basis" on d-day? I may have wound up in prison for the rest of my life. It was logic that pulled me back. And it's always logic that "comes the rescue" when I'm in difficult or personally trying situations. Emotions really do nothing but escalate or make already difficult situations more difficult. It's entirely possible to love someone with logic, I know, because I do it. Throw that logic out the window, and nothing is left, why not love the hot girl handing out shots at the bar? My emotional brain tells me "that'd be fun, go for it", where my logical brain steps in and says "But you'd hurt other people, you made a vow, it's not worth it, do the cost/benefit analysis". I can say, in my life, all the worst decisions I've made have had some deep emotional connection for me, all the best have been based on logic and reasoning.
