First, Focus on the "FK/IK Switch" panel of the CloudRig settings tab:
Each of the five switches are meant to be toggles with 0 meaning "use FK" and 1 meaning "use IK"; although, as this answer points out, they are actually implemented as "influence" so that you could have a rig that's partially controlled by each. (Don't try this at home.)
Anyway, you have the values all set to 1, meaning that Blender is ignoring the IK rig in each case. For FK set them to 0.
Setting Spine, Left Arm, and Right Arm to 0 will give you FK control, including the Rib Cage.
There's one other thing to know about using the FK rig. Open the FK panel. It will look something like this:
Those values are also "Influence" values, and they're to help animators. Take the Head value. If you leave it at zero when you rotate the Rib cage control, the head will stay at the same angle on the neck, bending with the rig. Sometimes you don't want that. If you change it to one, the head will hold it's angle as it moves. (It makes more sense if you experiment with it than it will from this description.)
Anyway, the whole point of these things is to make the animator's job easier. Sometimes it's easier to position an arm or leg by using IK, other times not. Sometimes you want the head to move with the torso, sometimes not. The various switches and influences are to give you that control.
(An example with the head. Suppose you rotate the torso on the Z axis. Maybe you want the head to keep looking at the same point, so you set head hinge to 1. Sometimes you want to move the torso to help move the head so you set head hinge to 0.