Wrong. It was 2. Look it well and you will see 2arrows:
You must be registered for see links
Yeah that's what we should call a side effect of his jutsu like Sasuke also had here:
You must be registered for see links
(You can see him sweating)
Or here:
You must be registered for see links
Here too:
You must be registered for see links
(he seems to have difficulties to breath and stay up)
Like here too:
You must be registered for see links
(here it seems like his life is even in danger)
I can show you a lot of scenes in that fight where Sasuke was in difficulty but that bring nothing. There were also scenes where he had difficulties to stay up and his mouth was bleeding because he had difficulties to maintain Susanoo for too long and launch his arrows.
But all that doesn't mean that even if they have side effects of their jutsus, they can't still fight. Proof is that after that Kakashi noticed the side effect of the jutsu, he was able to continue fighting with ease(he gave a blow to Sasuke that made him go way to the bridge:
You must be registered for see links
He also managed to escape quickly to a clone that manage to take him from behind, jumped and catch Naruto with ease:
You must be registered for see links
).
So even if kamui has a side effect on him, it doesn't mean he can't do that again and again. You are always saying that, if Sasuke throws 3arrows it will be over for Kakashi, but what you have forgotten is that even in the fight against Danzo, he only manage to throw it 3/4 times(forgotten) and even during that, he had side effects of his jutsus.
Kakashi is not the only one who will get tired after that if we consider that the fight would have occured at that time.
I say it because time has past since that. Now it seems Sasuke control Susanoo more easier than before, and Kakashi can fight during 2days against 7swordsmen+haku+2guy with KG+5Jinchurikis along with Guy. So maybe their stamina are far more impressive as they were at that time.
Yeah the fact that Onnoki made Gaara's sans lighter made it more easier for Gaara to catch Madara, but that doesn't mean that even without it, he couldn't. It's not Onnoki who helps Gaara to control sand. There was sand near Madara. Even if Onnoki wasn't there he could have control it. So nothing proves he couldn't have pull out Madara with the same way.
Also, yes onnoki did what you think but now it's Gaara's new ability. So we should consider that his sand is now lighter as before because the current Gaaras sand is lighter Onnoki or not.