Yes, when they decided to visit 1795, it was to undo Barnabas's villain status. By showing he was a victim of Angelique's curse, it gave them permission to write him as a hero of the piece since they must have gotten a lot of grief from the network about having a vampire as the main focus of the series. Then they set up (quite well, I will add) the circumstances where Barn had to go back to 1897 to save the Collinses from Quentin's Ghost. All his other subplots in 1897 were probably too much, but at its core he went back in time because David---arguably the future of the Collins family---was at death's door. Parallel Time just comes across as another excuse to have the actors playing different parts, subverting the status quo and not having to buy a lot of period costumes. It's fun, but it introduces an element of "What is it about Collinwood that allows them to shift into parallel universes?" The time shift stories were due to a seance gone awry and those nifty I-Ching wands, either of which could in theory happen anywhere. Having a part of the mansion where one can just walk into another universe sort of confirms all those hand-wringing scenes where Mrs. Johnson swore that house was cursed. Up to that point, the wacky goings-on were caused by Angelique, Laura, Nicholas, Adam, Sarah, Leviathans, Count Petofi and yes Barnabas....all of whom were outsiders who showed up to cause trouble. With the Parallel Time plotline(s) they changed tactics to say that it wasn't just outsiders bringing the supernatural to Collinwood---it was already there. Not that the writers thought that much about it, of course.