Oh sure; everyone else gets to have hammers, axes, swords, even a bloody scyth.
This has always been a problem of specialist fighters (and other classes). If you make a disarm specialist, you are going to lose half your feats against an Owl Bear. Few combats can't be won by damage. But a lot of monsters can't be overcome by damage-substitutions. Lot's of them arent disarmable, or trip-able, or stun-able. Quite a few can't be sneak-attacked, or crit (although pathfinder reduced those, there are many). But almost every one can be power attacked.on the other hand, a power attacking fighter spend his feats in that feat chain to get the DPS effect.
The problem is that the dm of most games throw monsters that require the DPS and a dex fighter gets blasted away.
Freeport is 3PP stuff from Green Ronin Publishing and didn't the OP say they couldn't use that?Freeport included a weapon enchantment called "Adroit" which allowed the user to sub DEX for STR modifiers to hit. I don't have it in front of me, but I believe it was a +2 equivalent and did not require the user have Weapon Finesse, and was limited to slashing and piercing weapons. Perhaps a +1 enhancement which makes the weapon Finessable would be a reasonable alternative. Of course, this means sacrificing alternate enchantments which would enhance damage.
Ultimately, though, DEX fighters have a different skill set. If you're trying for massive damage, that's the domain of the Brute, not the Swashbuckler.
As long as organized play is not a problem, I let my players spend a feat to make weapons finessable(sp?). It's like learning a fighting style.
And I let them do it with scimitar for free. Just feels right.
Damage is more the issue, as I'm not aware of anything that lets DEX sub in for damage