Well, if you're talking about panting... Kizaru was panting, too... Except in his case, it was drawn, not written in the dialogue like Ray...
And by damage lines... are you referring to Ray's overcoat? Because otherwise, neither Kizaru nor Ray has a scratch on him... Wait, Kizaru's got one cut on his cheek, but that's because he wasn't paying attention to Ray in the beginning.
And I'm not sure where Kizaru's making a joke... If you're referring to his response to Ray's complaint about his age, I'd have to disagree that it's a joke... It was more of an exasperated cry of outrage that Ray was thinking of taking care of Kizaru and then going to help the Strawhats. He says, translated (with a bit of interpreting to make things smooth), "Wanting more on top of stopping a "Marine Admiral", then I've no room for dignity. Cut that crap out." Why? Well, like Kizaru said, Ray was holding off a MARINE ADMIRAL, and Kizaru says you can't (and shouldn't) ask for much more than that, especially from a long-retired swordsman/pirate veteran, who talks to Kizaru as if he were a kid (or a young man at best) and obviously thinks he should be whooping the Admiral's ass instead of settling for holding him at bay. (Side note: On the other hand, Kizaru addresses Ray with a certain extent of honorific form (if you were reading the translations/scanslations, probably wouldn't come across as clearly), indicating that Kizaru definitely does not take Ray lightly and acknowledges Ray's status and strength.) OK, summary, I don't believe that Kizaru was at any point making a joke.. if he sounded like it, that's most likely just his personality/habit of talking.
(Since you ask for feedback on four points, I guess I'll make this one, too... Grr, typing way too much -___-) As far as Ray being on the defensive is concerned, out of the few cuts we see of the two fighting, Ray is on the defensive in 3, Kizaru is rudely and unexpectedly slapped in the face (well, slashed) in one, so I guess Kizaru is ahead in points there. But that's not really enough for me to believe Kizaru was necessarily winning the fight... Ray may have had his hands rather full, but it's not like his mind was completely focused as well...
OK, I'm gonna go watch a play now, so here's to waiting for another long week for the next chapter of OP!!