Although the wheel broke due to no fault of my own other than normal wear and tear and what I suspect to be poor quality of parts, taking the hub apart taught me a bit about the mechanics of how it all works.
HOW LOCK NUTS WORK:
For some reason, I had tried unlocking both bolts from a single side simultaneously rather than loosening the outer one before touching the inner bolt. Duh! Two wrenches are needed. Since I don't have two 17mm ones, an adjustable wrench can be used as well.
Unlock the outer bolt first by turning the wrench in the opposite direction as the inner bolt. Don't touch any of the other components prior to this step!
HOW A CONE WORKS:
The purpose of the cone is to secure the ball bearings to the cup. Proper adjustment needs to be maintained b/c if it's too tight, the ball bearings won't roll smoothly even if they're greased correctly. If the cone is too loose, there will be lots of "play" between the axle and the wheel. This won't necessarily warp the disk brakes, but it will have that effect. It won't spin smoothly and can wear out the brake pads unevenly. Having a loose cone can also put uneven pressure against the cup as the wheel is spinning. Roads cause vibrations which will inevitably alter the tightness of the cones.
Maintain proper adjustment of the cones as needed by buying a cone wrench. Don't be cheap and try squeezing in a regular wrench especially when the wrench is only $4.99 at Performance Bicycle when price matched with their website - $7.99 otherwise. It's pretty ingenious how the manufacturer, Spin Doctor designed a single two ended wrench with 4 sizes.