I assume you stroked that 100? out because you re-read the datasheet, which says it's range is 100-20K?.
1/2 that power is a bridge too far for a digital pot.
Again, it's not a problem if the actual voltage and current values across its range are within the specs of the digital pot.
Just because it's a 2W pot, it doesn't necessarily need that capacity in the application.
And they can only be used in Ground-referenced applications.
Well, you should probably look at the datasheet.
I quote:
The ground pin of the AD5293 is primarily used as a digital ground reference. To minimize the digital ground bounce, the AD5293 ground pin should be joined remotely to common ground. The digital input control signals to the AD5293 must be referenced to the device ground pin (GND) to satisfy the logic level defined in the Specifications section.
This requirement is no different than having the Arduino control, for example, a MOSFET driving a 50V motor, with the grounds connected together, and the aArduino pin driving the MOSFET's gate. One thing to keep in mind is that a ground on one piece of equipment can be conected to a non-ground on another device, as long as care is taken to not connect any other parts of the circuits together in such a way that bad things happen.
And, again, the circuit details extant are, basically, nil.
And that's why I keep saying "as long as the voltage and current requirements are within the capabilities of the digital pot".
And yes, the circuit needs to be investigated. Were I doing such a project, I'd have a look to see where the pot connects, how it's connected, checking the voltage across the endpoints, and across each end-point to wiper, current through the end points, current through the wiper, all measurements taken through the full range. I'll be very surprised if one could not find a reasonably priced digital pot to take the place of the existing one.
[Also, as it's wirewound. It's not unthinkable that its inductance, therefore, may be essential to proper operation.]
Highly unlikely. It's not as if we're talking about multi-kiloHerz signals here. This is Ag equipment, after all.