You know what the densest (and therefore the part that has the greatest penetrating power) part of an airplane is? Well, it's not the stale pretzels and fluffy pillows in the cabin, it's the near solid mass of titanium, steel, and aluminum of the engines. Why didn't the engines punch through the wall?
And if the non-fuselage parts of the airplane didn't penetrate the wall, but instead sheared off and just bounced off the wall, why isn't it scattered all across the lawn in front of the pentagon? In the immediate post-impact pictures, there is no airplane wreckage visible.
Seems weird to me.
If you are really suggesting that the wings and tail folded in towards the body of the aircraft and then went into the 16' hole that you claim was made by the fuselage.... well, you have a poor understanding of physics.
edit: Interesting link
Interesting link #2
Link #3
Green arrows show where the "wing roots" should have impacted. Note lack of damage where tail of plane would have hit. Yellow lines mark the support columns (~10ft apart).
Impressive that a guy who had only had a couple weeks of pilot school managed this direct hit while going >500mph.