The Apollo program, as impressive as it was, was never expected to be extendable to a colony effort. Rather first a space station was to be put in orbit, then on-orbit refueling, then space 'tugs', and then you could send up things that could land on the moon and ship additional building materials there.

That said, I found the hovercraft idea interesting since the benefit of hovercraft are completely negated by the inability to push against the surface for turning force and thus to re-capture forward energy into turning energy. This is a huge problem with lighter than air airships as well. Asimov should have known that.

The IIS gets regular resupplies to keep its environmental support systems operational and habitable.

Cost per kg from Earth to Lunar surface argue otherwise.

A multi-national consortium can barely manage to sustain operations of a 6 man crew in low-Earth orbit.

2. I bet we could figure it out. Again don't see any reason why it is not possible. Very little research has gone into that particular problem which I think is the main reason it has not been done.

Hardly irritating - that's my job, which I enjoy.

Sure, moon colonies would require enormous effort, staggering cost, and some new technology. The problem isn't the engineering challenge; we put people & equipment in a habitable box, and brought them back, using half-century-old technology. The problem is the cost far exceeds the payoff for anywhere close to the foreseeable future, and the scenery there is about as interesting as Death Valley (briefly compelling, but you wouldn't want to live there).