[Quanders]

I noticed the threads right after the turn of the millenium, but, in the interest on Heinlein the contemporary - could we do him the sacred honor of a discussion of late?

I have a few questions I have not been able to get answered by searching reviews of his tale.

Generally, is it the earlier sf authors that seem to believe that lunar peoples will dwell underground? Radiation shielding, no doubt, but what about all the other orbiting hotels and colonies? Do they fare more weakened?

The catapult - - why do revolutionists utilize this and not a mass driver aimed at earth? (looking for a scientific explanation if can get) Does concealing the catapult override this possibility?

Moons gravity - hurtling rocks from the "~gravity advantage down to earth"
Is it true, from a point on the moon there is a potential downward fall toward earth?

Pressurizing wheat and other foodstuff containers en route to Terra.
Would this it really be necessary to pressurize food holds?

I see the writer's talent, and the value of the work, but some of these facts still linger.