Well, there are 2 problems as I see it:
1. Stack and Reach will most likely make it uncomfortable or ugly. Stack and Reach is the vertical and horizontal size of a frame. The Fuji D6 is a tri bike which means it has a longer reach and lower stack than most road bikes. To illustrate, the stack and reach on the medium is 51cm and 40cm respectively. Just to illustrate, a 56cm Cervelo road bike has a stack and reach of 56cm and 39.5cm respectively. So either you're going to have to ride a really aggresive position with the bars way down low OR you're going to have a hideous stack of spacers and an upturned stem.
2. Geometry will probably not handle ideally. Fuji actually uses a more "road bike" geometry than most tri bike makers, but still the weight is designed for a 77ish degree seat tube angle. Once you get the saddle back to a normal road position it will likely handle differently than designed.
I would get any number of aero Road bikes like Felt AR, Cervelo S series, Ridley Noah, etc.