That was awesome.
The doctor in the first story probably got off the easiest. Yeah, he ends up in a coma, but he's reliving the orgasmic sensation of his actions, so at least he's peaceful. Could have gone without seeing the gory stuff with him mutilating himself, though.
As for Carrie and Jack, I sympathize with them both. The transfer was just an awful idea from the start, but that's how Haynes worked, he would reach these people at their most vulnerable moments and propose a miracle that seemed impossible. And he said it himself: the real reason that the transfer failed was because it took away any semblance of privacy from Jack, and any agency away from Carrie. None of the experiments were reversible, so the guinea pigs were stuck with the consequences. TCKR knew that too. The point was to get enough data to do the same procedure on someone else, having worked out all the kinks on the previous subjects. That's why Haynes and TCKR never charged for the services.
Still, the needle tips over to Carrie slightly. One thing I noticed was that when Haynes brought up the transfer to Jack and Carrie, Carrie immediately agreed, but Jack was more reticent. Still, he went ahead with it. Years later, when it came to transferring Carrie's consciousness to the stuffed monkey, Emily (Jack's new GF) agreed, while Jack was reticent, but went ahead with it anyway. Jack let himself get swayed by others when it came to major decisions, so it wasn't surprising that he relented on everything. Emily probably gave the stuffed monkey to Haynes and told Jack it was lost. And Jack willingly accepted that, because he wanted the whole thing to be over and done with anyway.
Clayton's story was the saddest, and it's not surprising that racists and White supremacists were some of the most gleeful watchers who pulled the switch. Hopefully his consciousness isn't in the souvenirs. I know Haynes' story started unraveling at that time, but I think that was when the poison really took affect, so that could be it.
I don't think Nish having her mother's consciousness in her head is a good idea, despite the happy ending. But maybe there was a way to transfer her mother and Carrie into something else, or San Junipero, like others have mentioned.