re: Migrating on Earth
I've got a cousin in the US who never visited Europe while I've been 11 times to the US and visited more of the US than he ever did. It's also thanks to a larger number of vacation days we have.
Why should we care about future generations of cyborgs who would be living on Mars and adopting a set of values, priorities and a culture so different from ours it's going to be very difficult to understand each other? We already have difficulty undestanding each other on Earth.
We should try to pay more attention to what we're doing to our own planet before considering Mars as a second planet.