there's really no benefit considering the brake pads create a biting surface to the current rotor. the brake pad is what creates the friction, therefore giving you your braking force. the rotor is just there as a mating surface. and i'm not sure either why you would need to remove the axle nut, well, unless you are removing the axle. but i'm not that familiar with newer model specifications.

 

That should work fine. Just get a length of pipe that will slide over it and use that as a cheater bar.

 

On older models the nut does not have to come off. The rotor simply drops onto the studs like many cars, but there are also two Philips head screws that hold the rotor on inbetween two of the lug studs. If you were to take a wheel off and see those Philips screws, it's almost certainly the same configuration. You do have to take the caliper bracket off first.

New rotors are cheap enough that few people bother to turn them. If your rotor is bad just replace it. Always install new pads too or the unevenly worn old ones will try to unevenly wear the new rotor. You will also have poor braking performance because of incomplete contact between the pads and rotor.

 

You'll need a impact wrench to get it off, I'd say it is 32mm, and to remove the rotor just undo the calipers and it will either come off with a little force(a rubber mallet works great) or they may have the little screws that hold them on if that is the case you will see them in plain sight.