re: The time factor
It's the time needed to go to Mars and back that makes me favor the Moon.
The longer a missions lasts, the higher the chances the crew will get disabled by something nobody had trained for or even expected.
Exterior, technical or human factors abound.
And the other related reason is about justifying Mars as a place to settle on.
We don't know how many settlers are needed before a colony can become self sufficient and thrive independantly from Earth.
I'm sure it's many many people !
Besides, when 20 recent impact craters were found on Mars (thanks to MGS) and they all appeared since 1997....then we can wonder how safe Mars is.