A cestus would be interesting, but it would be very strange since most military dwarves would probably be wearing gauntlets already.
I actually think the game already has a good repertoire of swords, but most are foreign.
The longsword is the dwarven two-hander equivalent.
The short sword is fine as it is -- suitable for both stabbing and slashing. I don't understand why you would change the slashing attack to blunt, though. Are they slapping the enemy with their swords? That's already defined two attacks down.
The large dagger is probably best for a stabbing weapon. You could "buff" the dagger's stab to make it better than the short sword stab and leave the slash alone as it looks pretty crappy anyway right now. Rapiers seem out of place with Dwarf Fortress. Even if you added a rapier, it would act like an inferior spear.
For a slashing weapon, the scimitar already has superior slashing attacks but inferior piercing attacks compared to the short sword (I think? Not too sure how to interpret these raw numbers). You could exaggerate that a little more... I don't use foreign weapons so I don't know how big of a difference they are right now. Alternatively, you could add a falchion with no piercing attack but an even better slash attack, which would be great for cutting down unarmored opponents.
I think defining any other swords would be superfluous. They'd all act similar to one of these in combat or would be some mix between them, especially because there's no concept of melee weapon range, maneuverability, and other fine details that differentiate most weapons from each other . Of course, you could define clearly inferior or superior weapons, but then no one would forge the inferior weapons.
Still, being able to forge these weapons (along with the pike) and adding in a 2H axe and hammer (with similar attacks as the 1H ones but with superior damage since you're sacrificing a shield/second weapon) would be cool. Also, I wish all weapon types had different professions...