After using Mountain Breeze, you can not use Radiant Explosion. You have to wait until the character is idle in order to use the skill.
https://gyazo.com/166a05cd071eaaa7c0f5b6dc00971d4c
WHen using Mountain Breeze, if you move the camera to reposition yourself, only the iframe part will change direction, while the Super Armor part wont change even moving the camera.
The second video you link is the reason why all archers say it is quite useless. We dodge the first skill damage just to take the second in the back... is ridiculous. I don't think is a bug. All our skills have a part of theyr animation where we are unprotected, or stucked in animation, or something else that let the enemies punish us.
For the first one i think is a bug, probably we will see a debug in the next patch, just wait ^^
Thank you for the info!