How would one manage to adapt to the day cycle, orbit, sunlight, jupiter brightness and such?
Yo don't need this. You will live in a base. probably underground, lighting will be artificial anyway. You may use any day/night cycle you wish. I would like to have 25-28 hours long "day" :)
Jupiter and the Galilean moons are visible.
The most interesting picture is on Europe - very large Jupiter and sometimes Io and Ganymede are looking twice larger than Moon from Earth. From Callisto they all will look smaller than Moon, so no epic selfies in front of moon passing near Jupiter. Europa have too large radiation level though.