I just speed-read this thread so I'm sure I missed some things. My thoughts:
1. Regarding juror #17 "not deliberating": I know jurors are saying #17 "wouldn't deliberate," but then they describe what she said during deliberations--that she wanted to focus on the journals, that she thought the DP would be revenge, etc. If JSS was told this juror was "not deliberating" and then questioned #17 and/or the other jurors and got this information, she COULD NOT legally have removed her from the jury. Steadfastly refusing to change your mind from day 1 is not the same as refusing to deliberate and is specifically permitted by the jury instructions.
2. Regarding juror #17 having prior knowledge of the case: Prior knowledge of the case is fine as long as you answer truthfully about it in voir dire. I don't know if this juror did answer truthfully, although I'm 100% sure I saw a tweet about a juror who had seen the Lifetime movie. It would have been improper, of course, for juror #17 to have brought up extraneous information in deliberations. Do we know whether the jurors actually mentioned this to the judge? I didn't see anything about them telling JSS about the Lifetime movie, etc. If they had told JSS, the appropriate way for JSS to handle this (assuming the juror had not lied in voir dire) would have been for her to instruct the jury not to consider any information other than that presented in the trial. She COULD NOT legally have removed the juror for mentioning these things in deliberation unless the juror insisted, after instruction, on considering the previously heard information.
3. Regarding juror #17's feelings on the death penalty: Again, I don't know what she said in voir dire. But it sounds like what she said in deliberations was that she "absolutely" believed in the death penalty but couldn't say under what circumstances it should be applied. This information WOULD NOT disqualify her from a death case and it would have been improper for JSS to disqualify her for not being able to specify under what circumstances she would vote for death. As to her statement that the DP was just "revenge"--in light of the other statement that she "absolutely" believed in the DP, I wonder if she said that IN THIS CASE she believes the DP would be revenge. If so, JSS COULD NOT legally have removed her as being disqualified to impose death.