Maybe I didn’t state that correctly, I meant that the defender could divide successes as wanted, choosing what attack to block and in what measure.
Maybe not overpowered but dicy, as you could render the block useless if the attacker spends all the dice but one on the other attack so, at -1D cost, you could strike your second attack against no defense. I don’t know if that’s the original intention as in this post (Two Fisted Fighter Training - #6 by Thor) @Thor states that the double strike it’s not very useful.
No, no, just making clear that the opponent would be at advantage even if you use again your sword, it just applies no penalty as it’s the same weapon length.