Kemp isn't strong enough to do this but...
I think Breeze was Ghost's father, and was probably a dirty cop. Uncle Gabe said he hadn't seen Ghost since the night his father died and Ghost tells Tariq that he was his age when he killed Breeze.
I also had a theory in an earlier season that Kanan and Ghost are half-brothers, it would be possible that Kanan as the older brother was wild/ruthless enough to be in the game but their pops (Breeze) felt James was too smart and tried to keep him out and legit like James is trying to do with Tariq now. Ghost wanted in and when Breeze wouldn't change his answer he killed him to force his way into the game. Why else would Kanan care about Ghost offing someone to leave the spot open for him? And if Ghost was 16/17 that leaves a mid-20s Kanan time to "raise" him.
Without their father's guidance Kanan was content being a street nikka forever while Ghost wanted more. I also think Q is Gabe's son and is the one who's been following Ghost, and in my theory would be Ghost's shooter. But Kemp is too linear and it'll be Tariq.
When did Tariq cut a deal with the Feds to record Ghost? And it would be unnecessary since Tasha tried the Terry Silver angle.
That could be a point of conflict for the show. Ghost made it out while his son is repeating his mistakes, on opposite sides of the law. And it would be interesting since most father-son dynamics have the father as the outlaw/villain. Angie as a Fed spent 5 seasons loving, hating, hunting, and covering kingpin Ghost so Ghost could do the same for Tariq.
Proctor has been in Ghost's life for a couple of months, everyone else he's known all his life.