Just a guess, but I would suspect most folks try moving body parts by dragging them initially, but give it up and start using the dials pretty much exclusively (after getting more comfy with them) because of the unpredictability of trying to drag parts through 3D space.   As you point out, the problem is that in moving one part, you screw up everything attached to it.

So, I've really not done it in years, but no one else has answered yet, and a few things did come to mind, if you really do want to drag to pose:

• you can lock body parts you don't want to move (such as the chest in your example) from the pulldown menu (Objects -> Lock Actor).  

• Turn on "Use Limits" for the figure to keep joints from bending beyond natural limits.

-Switch to bounding box display for making major adjustments.  (display responds faster)

-Get familiar enough with the effects to know when to use or turn off Inverse Kinematics.  ( IMHO - Turning IK on, then using the dials to translate hands & feet is pretty close to the more natural sense you get by dragging bodyparts)

-Collect pre-made pose sets for a decade as starting points. ;-)