"Felony Murder" = when a death occurs during the commission of an "inherently dangerous felony.". It doesn't matter that they didn't intend to shoot the victim . The mere fact that you were committing a felony and killed someone can make you guilty of felony murder.
It could happen but you have to get 12 people to agree it was murder. That is a pretty high hill to climb. I see a jury compromising on some other wrongful death charge.
Nope. There's basically two elements to a Felony. You were participating in a Felony, and someone died. That's it. If Arbery had taken the shot gun from the Michael's kid and killed him with it, since father and son were committing a felony at the time of the death, daddy is still guilty of "Felony Murder".