>>1) Having wings in the first place (An air force requirement, now rendered null by the air force abandoning the shuttle)<<

Incorrect. NASA had independently arrived at the need for a 1200-mile cross-range requirement *before* DOD was involved in the program. NASA realized it needed the cross-range for abort options, hence, the wings.

>>2) Having the shuttle mounted below and behind the ET, not on top of the stack like all other rockets (A feature resulting from the desire to have reusable main engines in the Shuttle itself)<<

Incorrect. It has nothing to do with the reusability of rocket engines. The orbiter sits where it does because of the lift produced by its wings during ascent. The forces are manageable in its present location. Putting the orbiter on top would have introduced killer bending loads on the stack. This is an issue being closely studied right now by the OSP folks upstairs in my building.

-Kim-