Many, very many, cooks boil the ribs before the grill. It makes for a more thorough and cleaner cook. It doesn't take 8 hours. And 'liquid smoke' is not something I would ever buy.
Essentially, you made slow boiled ribs in a bag, justified by a coal fire. I am lost. I do not understand the point of all of this.
Boil the ribs in bags (not for any hours) or no bag at all, if you want to, with whatever spices you want. And then grill them. OR, put them in a slow-cooker overnight, with any spices you feel at the moment, and watch them fall off the bone the next morning.
I did not catch the point of all of this?