I think you need to take the rear drive off and look at those splines too, if they look as bad as the ones on the tranny.....
I know those splines can be rebuilt, but it means opening the tranny and getting the driveshaft out , not too bad of a job but the driveshaft may have to be shimmed properly , so you would need a shop manual with the procedure for that.
For the pushrod, you need to roll it on a piece of plate glass to really see if it is bent or putting it on a drill may also give you an idea.
While you are in there you may want to replace the O-Ring behind the big nut on the clutch housing, they do fail ....and still do on the newer bikes.But you want to take that clutch housing off anyway just to clean that "Rust Dust" from behind ,in case it makes its way into the rear main seal.
Pressure plate, housing cover, they may clean up, hard to tell from just a few pics,you better start sanding, don't worry too much that steel is pretty hard, I'd even hit that with an orbital sander and a wire wheel on an angle grinder. But the diaphragm spring should be changed for sure that is what applies the pressure on the clutch.