I enjoyed the pre-Barnabas episodes and credit their establishing the appeal of characters like Vicki, Elizabeth, Carolyn, David and Roger . By the time Barnabas arrived, we could suspend our disbelief of the vampire gimmick, as we had grown to care about the human characters, and were intrigued by how this "cousin from England" would interplay in their Gothic world. Perhaps if the series started out with the supernatural, audiences wouldn't have bought it, because we'd have been preoccupied with the premise, rather than have the leisure to focus on the dysfunctional Collins family, as individuals, whom we grew to know and love in 1966.
I just found a December 1966 TV Guide that shows DARK SHADOWS on at 10:30AM! Its competition was CONCENTRATION game show, the JOHNNY GILBERT Variety Show, reruns of BEVERLY HILLBILLIES or BACHELOR FATHER, and ROMPER ROOM! Ah, the 60's!
As for David Ford (Sam Evans), he popped up on SEARCH FOR TOMORROW in 1973, playing a psychotic, murdering magazine editor named Carl Devlin. See what happens to people who leave Collinwood??!!