@Technique:
CoA finds the weak points of ability users and is the "only way to oppose them." This is Oda's answer to all abilities [cliche as it is] but was very much obvious. Kuma's ability would be no different.
Rayleigh's comments support what I'm saying. He never implied it shut down abilities. He explained it allows them to attack weak points of DF users ending his explanation with turning logia's into tangible bodies.
Haki shut down Luffy's rubber body so it should be able to shut down powers like Buggy's or Alvida's. If Kuma has to touch something to repel it then it is plausible that he may not be able to repel haki attacks. Magellan just covers himself with poison so haki is only effective in that case if it protects the attackers weapons from being destroyed.
Then Mihawk doesn't have Haki? Haki blows make contact with Luffy turning him into a normal body. Swords would never touch Alvida and Buggy in the first place…well in most cases for Alvida. A little slippage shouldn't be able to stop any sword(unless Oda makes her ability that powerful) but that is a different subject.
All Haki would enable you to do in Kuma's case is overpower his DF's defense with brute force like Luffy did to Marigold. Its not negating the repelling properties of his fruit. If Haki did work the way you guys are saying then hitting a transformed Zoan with a Haki blow would be like hitting their normal self causing extra damage. I doubt Zoans would be given such a critical weakness of Haki ignoring they are in a Hybrid form.
so basically, you're saying haki is an ideal defense against only logia?
As well as fruits like Luffy, Mr.1, and perhaps Hina; not sure about Jozu. Their extra defenses are just by-products of their fruits true abilities. Unlike Buggy, Alvida, and Kuma's that are primarily defensive shrugging off blows altogether. Seem clear the main purpose of Haki was to give a universal way of dealing with Logias.