Connection to the steering column would be the big issue. There would have to be both a telecoping shaft as well as a couple of U joints to allow it to flex with the suspension, just like a driveshaft. That will make for very unstable steering input. On top of that, there's also the increased unsprung weight, very bad for suspension performance.
On the steering angles, unless that rack is set up to moove in 1 solid peice, with tie rods only where it attaches to the steering arms, there will be severe toe out on turn angle issues.
