If we want to give a planet like Mars -- less sunlight, slower spin, less gravity, different tides and magnetism, different tilt of its axis -- a habitable and

If we want to give a planet like Mars -- less sunlight, slower spin, less gravity, different tides and magnetism, different tilt of its axis -- a habitable and sustainable earth-like environment, can that be done even if given an adequate supply of everything? To get earth-like atmosperic pressure, the atmosphere has to be taller on account of the reduced gravity. To get earth-like warmth, more greenhouse effect is required. So earth-like but not here is not nearly earth-identical. Problems? How quickly would an atmosphere like that leak away from the planet? What kind of weather might it have? How do you fabricate a biosphere for this unhinged sci-fi environment that will choose to grow into one that will both tolerate and sustain a large human presence? How hard is that? Boldly go, but do your homework first.