RE: "It is said Mars moons are easier to reach than iur Moon because of a lower Delta V to get there. And therefore, Mars is also more accessible."

Not really. The argument is that it makes no sense to go to Mars through the Moon for this reason. If your destination of choice is Mars go directly there don't waste time and energy with a detour to the Moon. The Moon is more accessible due to time constraints and it's silly to argue otherwise. What's most accessible on the other hand is of little import. You pick destinations based on what you want to do, not how accessible they are.

The rest of your comments are similarly flawed. You raise real issues, but don't deal with the fact that they have to be solved to go to Mars whether or not you go to the Moon first. I don't see a single one that requires humans go to the Moon to solve. Satellites in LEO with test animals would probably be a far more cost effective way to deal with a lot of these issues and you missed the whole option of articial gravity.

Regards,
Mark