Mainly... was this an altered timeline set in motion (knowingly or unknowingly) by Sarah's ghost, where Barnabas, even as a newly-minted vampire, was a nicer one than he would have been, because of Victoria's presence, and his concern for her? Was he "originally" simply bloodthirsty, overwhelmed by the effects of the curse and bitterness? Was the pivotal moment when he announced an impending bloodbath, then immediately changed his mind? Did he not change his mind "the first time"?
Anyway, before seeing the end of 1795, I pictured Barnabas somehow being dragged off kicking and screaming to be chained up, which no one would have the power to do, granted, but I had thought the whole point was that he'd become an all-out monster, who then stewed in his maniacal juices till 1967.
I don't think that Barnabas was "nicer" because Vicki was there. As I read into the story, Vicki simply took the place of Phyllis Wick, so if that's true, Barnabas should've been just as nice and concerned about Ms. Wick as he was about our Vicki.
I also don't believe that Barnabas ever intened, even in 1795, to go on a bloodbath. It wouldn't be true to his character, because even at his most evil, he still had a conscience about what he was going to do or had done. Barnabas volunteering to be destroyed was something he did because he loved his family, and he knew that as a result of Angelique's curse that if he continued living, the last few family members that were left alive in 1795 would die, just as all the others had, because they felt love for him. So, he was basically removing himself from the situation. Unfortunately, Barnabas didn't forsee that Joshua was going to take pity on his son and simply chain him up because he couldn't bare to give the order for his death. This shows that Joshua loves Barnabas, and, as a result of Angelique's curse, he should've died an untimely death too. Details, details.
Ultimately, I think this ties into the other thread that was going about whether or not Sarah had precognition, because there are a number of reasons that Vicki could've been transported to the past:
1) Sarah knew that Vicki was falling for Barnabas and since Sarah didn't want any harm to come to Vicki, she sent her into the past with the hope that Vicki would realize what Barnabas is and get scared. Under this idea, it was then planned by Sarah that when Vicki hanged she would revert back to her own time. Unfortunately, Sarah underestimated Vicki's incompetance.
2) Vicki just so happened to get sucked into a time warp, in a sort of "wrong place, wrong time" scenario.
Those are just two that I thought of off the top of my head. There could be many more. As to which is really true? Who the hell knows?