Make all of the finger roots children of the end effector of the wrist chain. The thumb should be made a child of the wrist bone. Putting the arm together. Make the end effectors of the main shoulder chains the parent of their respective arm root chains. Get a null.
Position constrain it to the last bone in the spine, and then relax the constraint.
Parent both arm chains making them children of this null. Parent this hierarchy to the end effector of the spine. Make the hierarchy a child of the spine. Your upper torso hierarchy should be all parented together at this point. To join the two hierarchies, make the legs root the parent of the spine root.