It sounds as though your rear seaters were treated in much the same way as our RH seaters; "Don't touch anything unless I tell you to, which isn't very likely",
I can't speak for the York, other than to point out the obvious that as a development of the Lancaster its config was pretty well laid down at birth.
As to the Hastings it had a civvie variant, the Hermes, which indeed boasted a nosewheel. The reason that the Hastings did not was put down to the Army's requirements that it should be able to carry "external stores". These could only be attached by access from underneath the archetypal tail-draggers elevated nose. A beam could be attached between the two main undercarriages, and a field gun and jeep could be hung from it with suitable parachute packs attached. The co-pilot had a release mechanism to hand, a glorified old fashioned lavatory chain arrangement. On take off if anyone as much as sneezed he was briefed to pull the handle, jettison the external stores, and it was hoped that the aircraft might then be able to climb away safely from the presumed engine failure.
You are right though, loading transport aircraft directly from the back of a truck was always a prime consideration. In the 60's the competition for a short range transport was entered by Handley Page (with the Herald) and Avro (with the 748). The former was the obvious choice, for with its high wing, its sill height was just right for that purpose. However Handley Page was resisting the Government's rolling up of the many airframe manufacturers into just two: BAC and HS, so was doomed to lose the contract. To win it, Avro had to invent the dreaded "kneeling undercarriage" in order to make its low wing aircraft "mate" with an Army 3 tonner!
The other anomaly of the Hastings that was also mercifully history when I got to it was its role as glider tug. Inside the rear nav lamp cluster was the cable attachment/release mechanism for that purpose. When one recalls that the Beverly started life as a proposed glider before 4 Centaurus were hung on it, the mind boggles!