Yes, that's exactly my own thinking.
I'm sure he fully understands his crime, and he's had at least a decade to get to understand it even if he initially didn't. Besides, even his own family have been fighting, they say, for him to be tried in the UK, so it's not as though even his nearest and dearest are saying he's incapable of being fit for trial proceedings.
No, their whole focus has been to keep him away from US justice.
And I just don't accept any argument suggesting he will lack any proper consideration of his 'human rights' if handed over to US authorities - partly because, illness or not, he should be properly culpable for his crimes (I think I read he perpetrated NINETY SEVEN hacks in all ... that's a considerable effort, one that must've taken some time, and been highly purposeful) ... also because I can't buy any hinted-at suggestion that the US system is incapable of giving whatever illness he truly has the appropriate care and consideration. Besides .. I'm not inclined to think he should receive more than the minimum such consideration anyway, considering the seriousness of what he's done.
As for where he may be allocated to .. well, assuming a British trial and 'guilty' verdict reached (and considering some of our judges, not to mention what we're bound to see from pressure groups here, who knows if that will happen ?) .. I'm guessing that few judges would be likely to give him a tough sentence; they'd be too inclined to weigh in favour of the issue of his illness. I can't believe any incarceration would involve any likelihood of anything less than a 'soft' jail environment, anyway - such is the socio-political climate over here.
And who knows, maybe even the EU Human Rights courts would step in and help him if by any chance I was wrong on any of that. I'm sure his family wouldn't hesitate to appeal to them if he did receive anything 'draconian' from our own court system. No doubt that's another reason for his family wanting him to escape US justice, so that this avenue then becomes open to them to pursue.