I am afraid most of your answers are wrong, I guess you are misunderstanding some of the basic principles.
First of all - changing the ligand doesn't change the oxidation state, for the change of the oxidation state you need a redox reaction, there is only one such reaction here.
Please elaborate why you think the formula of hexaaqua ion is Fe(H2O)6]2-, and why you think oxidation state of Fe in this ion is +2.