That looks like 4 things, not 2 .-.
Also, while Janny's logic is sound that benders could theoretically learn to Chi-Block, they have no reason to, and it would be imbalanced in the terms of the plugin. Benders in the Avatar world never learned to Chi-Block (Except for Amon) because they could already defend themselves with their bending, so why put time and effort into another form of martial arts? (On an added note, actually learning other forms of martial arts besides their own seemed to be limited to the Avatar, who would learn all the elements. And when you can bend all 4 elements at that point, who even needs Chi-Blocking? You can fly around!)
To start off with, it's not fair to the non-bender classes if their unique skills can just be learned by any bender who so chooses. Why be a non-bender if there's no benefit to it?
Another thing. In my experience, adding Chi-Blocking to benders makes for a horrible time in the arena or in the world for everyone else playing. They can paralyze you, or rapidpunch, etc, and then launch elemental attacks of their own while you stand there powerless. Back in one of my first servers, there was an Avatar who would paralyze you, then put walloffire on you, and attack you with whatever else on his hotbar. It would generally result in instant death. It takes little skill to freeze your opponent in place with Chi-Blocking, and then kill them with bending. You just need to get one hit in.
I know that it's possible already to give Chi-Blocking to benders/Avatars on servers, but if we're doing RPG, we should really think more logically about it. To conclude, Chi-Blocking added on to bending is no fair, no fun, and all in all illogical.