Join Date: Jul 2013
Location: Gatton, Queensland, Australia
From what I can see from your photo there does seem enough good thread left on the outside of the nut to allow the axle to be reused. Sure, the easiest cure is to replace both but if cash is a consideration taking a bit of time to clean the threads up, and removing the nut with a little care will see the axle just as strong and reliable as a new one. My only concern with not doing it straight away is if you did, for some reason, need to remove the wheel while on a trip.
It should be very obvious when riding a straight road if the forks were bent at all.
From the description in your second post I'd guess that the slide tweaked the handlebar that went down and bent it upwards slightly - which I am sure is the side where your mirror now hits the faring blade. The only cure for that is to replace the handlebars.
2010 Weestrom; 2017 Kawasaki Versys-X300; 1988 Suzuki GSXR1100