Tony mentioned dikkie lots of times in the show. So it makes sense he's a major focus. But I think Tony's story may be the c storyline.
My understanding, this movie is mostly about dikkie and the rising tensions on the streets between blacks and Italians leading up to the Newark riots.
dikkie Moltisanti was Carmela’s cousin, so their parents (Carmela’s father & dikkie’s mother) were siblings. So Christopher is technically Carmela’s second cousin