well the first one doesn't seem really fair, I say no to that because you basically disappear and randomly twist a guy's neck into an instant KO, which is unfair. So I'd say you should change that or delete the technique.
Now for the other ones, the Weapon Possession one, as long as the possesion of the weapon and the post where you attack with it are different posts, as in not in the same post. And also in the last attack, it varies with the target's strength, right?