I really like the idea of tricking the laptop to detect inputs from both controllers. That sounds like it would be a lot of fun and add a lot of value to playing through Final Fantasy games with a friend.

In the past, I have played Final Fantasy V and Final Fantasy VI with a few friends. You can get a lot of replay values out of certain games especially if the fan communities surrounding those games have made patches to adjust certain aspects of the game like difficulty.

I played Final Fantasy on the Gameboy Advance very recently and it had a noticeable lack of difficulty for the most part. When you play on an emulator, you can easily hold a button down and train very quickly.