@ the OP: Thought the post was a good read. You articulated well a lot of thoughts I had initially. It was hard to actually choose a side I wanted to be on, such that by the end I just felt like I was getting bounced around to the option that would be most palatable. I will say that I don't think that there is any hidden part of the Institute where you will find your son. I think things feel so strange in the workings of the Institute, and the other factions as well, because of somewhat poor writing. I feel like Beth had a great idea for how to make this awesome tense story, but didn't quite get it nailed down, from a tonal perspective, before they had to wrap it up and call it a day. With the way that the story concludes, I doubt future DLC will be devoted to a part of the game that most people will be through by the time the dlc launches. I could be wrong, but I feel like we would get post-story dlc, as opposed to in the moment stuff.
I wish I could talk with Bethesda and see what the split is in their own office about who supports who. If they ever do an AMA or something, that would be my first question. I'm honestly surprised that more people don't support the Railroad. In most of the opinions I read, a lot of people hate the Railroad for either being uninterested in helping the Commonwealth or being blind to the risk of synths/sacrificing human lives for machines. The first point is pretty hypocritical, since the Institute itself outright states they have no interest in saving the people on the surface, but the Brotherhood at least carries that as its main goal, even if they are a bit fanatical.
The attitude toward synths is at least, defensible, although it seems to me that it takes an insane amount of confidence to say that synths are absolutely not sentient and should/can be treated however. Leaving aside RP considerations, I feel like a sensible person in this situation, after going through the events of the main story, would have to give it some serious thought. If anything, I feel like the story sets up a great kind of social experiment... looking at how we do or do not justify our actions. So kudos to Beth on that front!
I personally always end up siding with the Railroad. Meeting Valentine is what always does it for me, especially if you finish his quest and listen to his speech at the end. He definitely has a soul of his own. Honestly, the whole debate makes me a little sad. If you have any appreciation for history, you can see parallels between what people say here and horrible events that have occurred throughout time. It is of course just a game, but the spirit of the discourse follows the same tired paths. It is especially sad because the PC is the hero and doesn't have real constraints that might otherwise be factors in the decision making. You can literally choose whatever you want to do, the end events are hardly impacted (except obviously for who survives) so I always found it surprising that the Railroad wasn't a more popular option. But I digress.
I think it's pretty poignant actually. I mean who better to render that advice than someone who knows how to process and sling the most epic of BS? More importantly, I think you are misinterpreting Deacon's character. His pathological lying doesn't seem to be a method of manipulation or survival but rather just a coping mechanism. Think about how preposterous his lies are (and disregard the reaction to his lies, I feel like the delivery of the lines is ridiculous... a rare misstep in what I otherwise thought was pretty solid voice acting) in relation to when he tells them. Lying is basically a joke to him and I wonder if that isn't because that's how he copes with the trauma of what goes on in the wasteland. You'd have to be a little unstable to not be crazy in the post-apocalypse.