Well, as we should all know from Gandalf's almighty plunge into the abyss in Lord of the rings, saying noooooooooooooooooooooooooooooooooooooooo!!!!!!
Can be very good for the magic muscles (grin).
I'm afraid I'm not sure about the enemy's attack increasing when you buy a larger sword. In Western weaponry, because it's traditional to wear lots of armour, a big heavy sword is more likely to be a good thing so you can batter through your opponent's defences. If their weapon is thinner, weaker, and less sharp than yours, your armour will withstand it better, so you'll be doing more damage.
Of course, in the japanese tradition things are very different, with speed and balance being more important than strength, sinse it's not usual to ware armour in that tradition. But even in the Japanese fighting tradition a better sword moves faster, has better balance, and is more likely not to break when the enemy parries.
Sorry about the minor lecture here, it's just that my brother is heavily into Samurai stuff (he even collects and practicies with replica catanas, Wagasashi etc), and I have a friend who does viking re-enactment, so she knows all the proper details reguarding how to club somebody expertly with broard swords etc, so I've picked up details of this type of thing from them.
Btw, yes! I have scary friends! I'd love to see somebody try and mug her, I think it'd result in a mugger with an extremely bad headache.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)