Need advice on create app like computer osciloscope

I need to create app, which is control app for laboratory device similar to osciloscope. Device is creating some high frequency currents and I need to visualize this freq change on some kind of a graph. App is for desktop Windows.

I want to write this using Qt, and for graph plotting I want to use Qwt project. I need to communicate with the device usnig D2XXX direct driver. The device has: UM245R

And I have a few questions.

1. Has anyone written such an app, maybe with D2XX driver and Qwt and can share his/her expierience
2. Is Qwt rigth choice for fast changing graphs, like in digital osciloscope
3. Are there some pitfalls I can ran into
4. Any other advices/recommendations/warnings when creating such an app.

Best Regards

Marek