In past creation kits, one set the level of the water in a cell. Not sure if this can be done globally or not.
Also, our moon is 1/4 the size of Earth and 1/80th the mass. We don't know the size and mass of the moons of Nirn nor the radius of the orbits, but they could be small enough or far enough away that their effect on the tides is minimal.
And there is a problem with the orbits because there is a problem with the phases as you can see there :
http://steamcommunity.com/id/pjmtlg/screenshot/523781054769783030?tab=public
http://steamcommunity.com/id/pjmtlg/screenshot/649878131770860393?tab=public
http://steamcommunity.com/id/pjmtlg/screenshot/649873533903849761?tab=public
http://steamcommunity.com/id/pjmtlg/screenshot/649878131770853699?tab=public
http://steamcommunity.com/id/pjmtlg/screenshot/649877898954029074?tab=public