Need advice on app like for osciloscope

Hi all

I hope my question does not break any rules,it is not my intention, though it is very general.
I'm very new to Qwt, I have some expierience with Qt.

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 2D 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.

Which type of graph/example should I follow for the start?
Are there some pitfalls I can ran into ? Like too high freq for smooth graph plotting. USB can deliver up to 1Mb, can this work in realtime ?
Any other advices/recommendations/warnings when creating such an app.

Best Regards
Marek