so the brake rotor is supposed to float a little bit side to side, but not rotationally at all. not sure which way you mean on this. as far as the side to side is the rubber pieces are fairly important but only at keeping dirt out of the splines, i would get some grease in there untill you get a new boot.
and as far as your wifes rear brake rotors im sure awk will be able to give you a solution for that too.j/k