re: Returning back from the Moon
It might be useful to explore the original concepts we had for going to the Moon, i.e. assembling the lunar vehicle in Earth orbit, fueling it with a number of flights from Earth, and leaving from Earth orbit, maybe even from the vicinity of the Space Station.
This would require no launch vehicles any larger than we are using now, and with the experience of shipping fuel and supplies to the Space Station, the technology is largely in place.