Part of what bothers me with "Tapestry" is its simplistic notion. Did young Picard ever have doubts about picking a fight with the Nausicans before he actually did it? And that couldn't have been the only questionable thing that young Picard did. I also found it highly unlikely that his life afterwards was so profoundly different that all he became was a Lieutenant Jr. Grade.
I feel like they had a good idea and pretty well just hashed it together. In some respects it seems more like a dream rather than a Q manipulated event. Indeed I think it's more likely that as he lay near death Picard was simply hallucinating/dreaming on the edge of unconsciousness. And this despite the fact that at the end Picard seemed to believe that Q was actually involved.
In a way this really isn't that different from a holodeck story.
In a way, this really isn't that different from indefensible nonsense.
Here's the thing: it did happen. When you wake up, you know if you just had a dream. Picard knows he didn't. So it was real.
Also, it is completely plausible that his life would be altered based on this event. This isn't some everyday occurrence here. Either it's the day he got stabbed in the heart, or it's the day he alienated his two best friends from university. As for myself, I still have both my heart, and my best friend from university, so I can understand how the loss of either of those things could have had a profound effect on my values, my self-worth, my goals, and my very direction in life. If you say such an event is unlikely to drastically alter one's life, then I say that you're just plain wrong. Lives have been altered on far less drastic choices than this one (and this one is, as I said, pretty drastic.)
In a way, this episode has the same theme as the TOS episode with the split Kirks, the one with the transporter accident. The idea is, basically, that to be a success in life, one must be a bit reckless, less cautious, more courageous and maybe even a bit stupid. Kirk learns that lesson one way, Picard learns it another way. And for my money, the TNG version is far less juvenile and silly, far more emotionally affecting.
And I believe you've even stated why it is you're no longer enjoying the series - you lack an emotional connection with the characters. And because this season is so character-based, an emotional connection is probably necessary to enjoy it. But see, about that lack of emotional connection, that's an obstacle that lies in your own head, not on the screen. You may just as well say you lack an emotional connection to the characters in The Godfather or American Beauty, but that doesn't make them bad movies - it just makes you a bad viewer, or at least one with different sensibilities than the filmmakers require of their viewers.
Look - Tapestry and Chain of Command are very well-produced pieces of drama, objectively speaking (or, at least, as objective as one can be about these things, which is more, I think, than some people would like to admit.) They are two of the more well-produced hours of science fiction television of the last few decades. If you just don't dig them, because you just don't really care about what's happening onscreen, that's a very cogent and illuminating review of your own dramatic viewing sensibilities, but it says absolutely nothing about the episodes themselves.
You had me on the lesser quality of season 5 - because you were right. And you were right about the first third of season 6. But now you've just lost credibility, I think. You're tired of the series, for whatever reasons your TOS-based expectations have supplied for you, and so you've lost the ability to be objective about its successes. (Imagine a film review of Blade Runner, for example, by a guy who just doesn't dig sf - it wouldn't be very useful would it?)