I guess I'm gonna clean this all up now by disproving Sanji's speed and durability:
Sanji dodging lasers was due to him having Observation and the lasers having a visual cue ( Queen saying the name of the attack and his eyes sparking when it charged up ), it's not exactly a speed/reaction feat, he just had common sense and jumped out of the way.
Compare this to Marco coming out of no where to intercept a giant ball of light from Kizaru ( Kizaru also has Observation, btw, and didn't see that coming still )
About him going fast enough to turn invisible: That'd probably work for a bit, but Marco will probably still be able to tag him/see him due to Observation Haki. And as Queen pointed out, after a while he's going to grow tired of it and stop doing it due to his stamina, so it'd just be like this eventually:
His durability is formidable, but Marco has dura neg ( if you want a full list for why he can hurt Sanji look at the one KingTempest made that I posted some minutes ago ) and Sanji's exoskeleton still has it's limits ( he did tank Queen's sword, but
he said ouch and it dented his facial cheek a bit. And it's the same for him getting his bones crushed, he still remarked that it stung a bit, he evidently
felt pain regardless ).
When was it stated that Kizaru is the fastest admiral?
Even if that was the case, that still doesn't change anything.
It's pretty obvious, since he can turn into light and travel at light speed, and that's mixed with the fact that he's fast even without his DF, just not as fast as he is with his DF.