The V-brakes would work well. I have found them to be a little more temperamental than disc brakes (to adjust), but a good adjustment on them should last a while. The carbon fork would definitely add comfort over an alloy fork.

As an alternative, check out the Trek Verve. That would be a perfect candidate for your father. It'll have a more upright riding position and much larger tires for more comfort. The Verve 2 model is $560 (similar to an FX 2) and has a similar 3x8 drivetrain. One big advantage, though, especially for the type of riding you cite, is the 45mm tires vs. the 35mm tires on the FX.