A late comment: I had thought some more about what Deuce says here and I'm adding a longish comment I had thought to post originally but didn't. So, my thought is that his comment about Thunderpunch having signed himself to a life of solitude seems very short sighted if not outright daft. I'm guessing it has to be an "inside insult" that pulls on his knowledge of TP.
First, you've established that few, if any, powers are unique. Some are common enough that everyone with them has a class name (ghosts, batteries, etc). It doesn't seem to be as extreme as the "Flying, Invulnerable, Super Strength" generic powerset every super-hero-universe seems to have bajillions of (the webcomic PS238 turns this on its head in a great plot line, by the way). But still, there are really few powers that are one of a kind.
Is Deuce saying, that nowhere in the world has there ever been another person like TP who could go through the same process he did? No one whose power was to grow? No one who could shrink other people? AND on top of that, that the scientists will never refine the process used on TP to produce alernate results (like the power without the size, etc)?
That seems, if not deliberately ignorant, then it is something he's hoping TP is too angry to think about and is just saying anything, no matter how dumb, to piss him off. Basically, he has to know something about TP that makes this a really effective jab. Because my first reaction to his comments here, was humor. I thought it was absurd.
Let's say "the redhead" died. Now he might find someone like say www.giantgirladventures.com/. Sure we all want who we want, but I'm talking from a plot angle, not as TP's friend who would try to comfort him.
Let's say that she freaked out at his size. Again, see above.
Was she another test subject who failed? That would just indicate that they will eventually make others like him because they have at least one other than him (meaning his power is not unique and very genetically diverse people can develop it) and that means there might be more.
There's no way to interpret Deuce's comments about TP's size where they are plausible. Unless there's more going on. Or if that redhead did something or said something to TP that he's never gotten over/recovered from. We've all lived in a bad emotional space when we had no reason to. I'm guessing TP has something like that going on. Where he has some guilt or shame "from" her, not necessarily "about" her.
Deuce must know Tyrone fairly well. I think he was trying to poke him in a way that he thought would hurt Tyrone personally. Deuce probably thinks theres a chance they can beat him, and he wants to provoke a full fight with him. Tyrone is conflicted fighting his old allies, he's just not a hard-hearted person.
I don't think that Tyrone rationally expects to be alone forever, but it's probably something he irrationally worries about. There's a girl he likes, and has liked for a long time, and might be too uncomfortable to try and attract her. That he's worried that either it would be a barrier, because they probably wouldn't be able to have a normal physical relationship, or that she'll find someone else in the meantime. He might expect they'll fix him eventually, but it could take years. He's conflicted about tying her up waiting for a solution. That either he should follow through and hope something will change, or let her go to someone else.
It might not be that easy to shrink him with magic or something, maybe it would mostly only affect human tissue, and not cybernetic parts. It could be more complicated with him.
I don't think growing is TP's power. It's that they tried to increase his strength, and it had the side-effect of making him grow over several years. It may have happened during puberty, and they didn't really catch it soon enough. They suspect they can change him back, but they are worried that any decrease in size will also decrease his power.
I think that natural powers are fairly similar, but that when you experiment on someone you often get unpredictable results. Tabitha didn't change like Annie did, although there are differences between them (Annie is smaller and was less developed). You also always have flaws at the start of the process, and you may not get the same result if you don't do things the same way twice, or you notice your mistake and change it. A lot of these superhumans seem to be experimented on in small groups, so you may not have many people or even more than one person who has had the same flawed thing happen to them. If something is thought of as a flaw, it's not duplicated.
Most likely, Deuce is the counterpart to Thunderpunch. He has similar powers and some of the same problems. While he is maybe green, he isn't oversized.
If they're discussing pawn status, then that's what Annie is... an experiment without consideration to her benefit.
I'm also taking a look at Thunderfist's stance with the origination that powered him. If he's keen on protecting their interests, a "what if" scenario would have him turning on poor Annie, most likely if she gets to the point of knowing too much.
But they don't imply it wasn't their own choices as well. Just that they should have been more careful to what was in their interests.
TP's background might not be a secret. There is kind of a repeating pattern of people not knowing how they shouldn't try to improve themselves. He knew Annie's name and is probably about her age, I suspect they know each other well.