Not only are you utterly rude and condescending, your comprehension skills are lacking. Being a master and being capable of wielding are different.
Dude Yen id is not a master.
He has the title because of Mickey.
Again hed have had some form of fight by now.
But he hasnt.
Just because Mickey willed Yen his keyblade doesnt mean he can use it.
Notice you said
Mickey GAVE it to Yen sid.
Isnt that the same as when riku GAVE Kairi his keyblade?
Again your proof isnt much proof.
In fact the fact that one can give a keyblade to someone makes your whole theory fall apart.