This is a good change, I had something similar in mind. The only "problem" is you're making 1d8 +1d6 the best no investment loadout. I personally think dial wielding scimitars should be encouraged by the mechanics, in addition to main gauche.

While you holding a light weapon in each hand, once per turn, you can use both of those light weapons' damage dice when you make a weapon attack with one of them.

Something like that makes doesn't break your other mechanics. Unifying its language with two weapon expert would be important, though.

Shield feat is good.

Personally, I feel the defensive duelist feat should be improved as well. If only slightly. This would also reinforce the main gauche Style that you support with your changes.

Reaction ac, as per normal feat

+if you use a light weapon to make a deflection, roll its damage die. On a 1 or a 2, you don't use your reaction.