Where the hell is Barnard and Rose at this point? Are they still "retired."

Yeah they're still probably hanging out in the jungle with Vincent. I'll say it's entirely possible, but not exactly probable that they'll kill him since the last time we saw them they gave a big speech about chilling the hell out and not trying to kill each other.

All the characters died. Some of them before Jack and some of them after Jack but they just died. Maybe they did YEARS from the final episode but they showed us they were dead, they were in the church. But they didn't tell us when au how.