(Now that I finally have some free time on my hands...)
I started writing this some time last November, a while after I'd rewatched the DW S3 finale and TW S2 and then tagged it 'unfinished' and never touched it again, partly I suppose because Christmas, flat searching anxiety, etc., got in the way, partly because this was never very coherent to begin with and always a bit too speculative for my taste.
But upon rereading, er, digging it up again, while I'm still not enthusiastic about it, I'm finding that parts might still be kind of interesting, and since this is the last chance to post it before it all gets jossed to hell by S3 (although OTOH I'm occasionally, sort of, very, very, quietly, still patting myself on the shoulder for that not-too-jossed post-S1 Jack/Ianto post...), I thought I might post the better bits after all.
Surprisingly enough it all started with Sleeper, although rewatching did nothing to change the issues I have with at least the first ten minutes of that episode. But then there's that scene with Jack, Gwen and Beth in the cell, after Beth's true nature has been revealed, which actually is very good. Like in Adrift it's hard to be on Jack's side here, because his brand of directness comes across as rather callous, especially on top of how he's treated Beth so far, but of course the tragedy - Jack's tragedy - is that he's actually right, and knows it, because he's been right about that kind of thing too many times. There's this what-the-hell-are-you-doing? look he gives Gwen, first when she reassures Beth that she's human because she's feeling human, and again when she tells her that of course they weren't going to kill her, that already hints at the space dividing them that will eventually lead to the confrontation in Adrift, where again, when it comes right down to it, Jack was right. Because anything Gwen says about feeling human is... completely understandable from her point of view, her age, experience, personality and background, just like her actions in Adrift, and I hate the way she keeps getting bashed by fandom for being a normal human being with normal human reactions, but from an absolute point of view - or from Jack's perspective - it's all useless, comfortable lies that only postpone the inevitable.
There's this line in Greeks Bearing Gifts where Jack comes into the tent and remarks that once, just for once, he'd like to find a party instead of a dead body, and obviously Jack pretty much already knew then that the Beth situation would end with a dead body too, maybe (although that's only conjecture) just as he'd known that there was something seriously wrong with her, with a certainty that in his mind amounted to proof rather than a vague suspicion and made him not even see a terrified woman any longer rather than an alien threat, because that'd only make a situation he wouldn't be able to change anyway unnecessarily harder and more complicated.
It's not that Jack doesn't have any emotions, I just think that over time he learned to compartmentalise them extremely well. The Jack who after almost a century can still get angry about the practice of shooting shell-shocked soldiers for cowardice allows himself barely any compassion at all when he sends Tommy to his death; something that needs to be done to save the world.
Part of Jack, maybe the part that was grounded in a happy childhood before it was all torn apart, grasped at and clung to the idealism the Doctor inspired when he first met him, but after more than a century and everything he's suffered through, seen and done during that time - and old school Torchwood certainly didn't kill aliens 'only as a last resort' and in self-defence: the way Jack spits 'That's what we do best. Wipe out aliens,' at Adam speaks volumes about the situation he's been in for much too long and the cognitive dissonance necessary to endure it - there's little enough left of that, and even Gwen, as much as Jack may appreciate the humanity and innocence she brings into the team, does not essentially change that, because experience is on Jack's side; it's rather she who has to accept his perspective, and then find her own way of dealing with that.
It's not necessarily a pessimistic attitude, just brutally, stripped-down-to-the-basics realistic, no illusions or dreams and barely any hopes - except for the big one, that he'd meet the Doctor again and he'd fix him, but I suspect even that had become a bit of a threadbare and bitter dream after all that time, however stubbornly he still clung to it, and that it didn't come as that much of a shock in the end to learn that his situation wasn't fixable, or returning to his life in Torchwood would have been a harder decision. Although it makes me wonder if the fact that Jack does often seem harder and colder in S2 than in S1 is influenced by the fact that he's finally given up the dream of the Doctor too, and instead is trying to re-orientate himself in a life and world that suddenly turned from something transitory and merely to be endured into something he'd chosen.
And unlike the Doctor Jack didn't have the luxury any longer of being able to skip back and forth in time, picking the best pieces, saving the day and not giving too much thought to the fall-out (which, granted, is also a kind of coping mechanism); Jack was forced to live, day by dreary day through a century that perhaps overthrew more ideals, belief systems and ideologies than any other; two wars that fundamentally traumatised and changed generations. It might have been fun when it was a playground for his self-cleaning cons, but probably not so much when there wasn't a chance of escaping, and for someone with his history, for whom it definitely was a burden to watch people die around him when he himself couldn't, even when he wanted to, this can't have been easy at all. And while the second half of the century certainly was - comparatively speaking - better, at least when you were living in the western world, towards the end it wasn't all fun and games either for someone with Jack's 51st century sexuality combined with his tendency towards survivor's guilt.
'It's just bearable. It has to be.'
(And that, on a side-note, was part of what bothered me so much about Mitchell's characterisation in Being Human. A whole century, most of it lived as a vampire, but when the local populace comes after him with torches and pitchforks for being careless enough to pass on what effectively amounts to snuff porn to a child, he's suddenly all OMG, this is what humanity's like, whine, moan, disillusionment? I'm not buying it. Sorry, but this is just sloppy writing.)
And of course that extends to relationships, because Jack can't ever escape from the knowledge that partner after partner will die on him, unless he leaves them first, like Estelle. Which is why IMO (and maybe at this point I should already add: on the basis or pre-S3 canon) Jack and Ianto have a better chance at making a relationship work than Jack and Gwen would ever have. Jack and Gwen's relationship is fraught with too many illusions and expectations on Gwen's side and the constant effort to protect her and thereby hiding part of himself on Jack's, while there's an essential gulf between then that only becomes fully apparent in Adrift, at the end of which Gwen characteristically turns to Rhys for comfort. Jack and Ianto are a lot more alike, and as far as moments of truth go, it'd be hard to surpass Cyberwoman. It might not be exactly a healthy relationship, but it's maybe more of a genuine connection, although for two people who apparently find something necessary to both of them in each other, a level of comfort and consolation, a bit of meaning, they continue to be pretty hard on each other, too. And while Ianto probably went into this not expecting or even wanting love any more than Jack did, it must still be hard on him, because Jack's more than a century's worth of immortality-related intimacy issues are still different from dealing with the trauma of losing one's girlfriend, even if it was under horrible circumstances.
(Actually, my wish for S3 would be some stupid romantic moment for once not (over)shadowed by the usual Torchwood doom & gloom. I kind of doubt I'll be getting it, though.)
And on somewhat related note - In Adam Gwen, Ianto, Owen and Toshiko have to lose the false memories that Adam implanted to become who they are/were before. Jack is the only one who is forced to lose (once again) real memories to become... what? What kind of person was Jack before the pain of those memories became too much to deal with and he started pushing them aside; the Jack with the memories, the painful ones, but also those of a happy childhood, the one who still had a sense of belonging somewhere? Is Jack, in a way, in this episode more himself than he's ever been before? It's remarkable that Jack in Adam is a lot warmer, a lot more emotionally open than we see him otherwise, not this cold, guarded man with all those layers of protective shields that make talking to him about anything emotional or personal an almost impossible task.
[ETA: In case anyone comments - no S3 spoilers, please!!!]