Riggerrob,
Have to disagree with some of your conclusions relative to pushers in general and the Cessna 336/337 in particular. Climb performance on the rear engine is markedly improved relative to the front engine. (Time logged in a 336 back in the sixties including caging each engine individually). Discussions with the owner of a Turbo 337 (also an aero engineer so we spoke the same language) revealed that in addition to climb performance, top speed and %power required in cruise were both superior on the rear engine. Jack Norris, Burt Rutan's Director of Propulsion on the design and the flight or the Voyager has written an excellent paper for the AIAA on the loss of propeller efficiency, relative to spindle performance, when the prop is installed in a conventional tractor aircraft. Another long time friend, Joe Brownlee, an FAA test pilot was assigned to the LearFan certification program was amazed at the performance of this pusher, relative to similarly powered conventional twins. Don't have all my stuff accessible as I type, but if you are interested I'll dig out the the title and number of Jack's paper.. My earlier posts on this topic go into why pusher props, facilitate attached flow over upstream surfaces and, operating in an accelerated boundary layer demonstrate higher propulsive efficiency. In fact, look up "Wake propulsion" One of the examples, a long range small cruise missile with pusher counterrotating fans showed an installed propulsive eff. exceeding 100% (this is relative to the propulsor operating in a free field).
The original Consolidated intercontinental bomber proposal involved four engines , two tractor, two pusher. Powered model wind tunnel tests conclusively demonstrated that four, and later six pusher props made the B-36 a design success.
I'd be interested in seeing disagreeing arguments.
Dynasoar