She could learn to use one as a focusing tool, yes! Our understanding is that staves are generally laced with lyrium to allow them to channel and enhance magical energy, and in Thedas, Hermione is drawing power from the Fade similar to native mages--so she would likely feel that, similar to feeling some power inherent in a wand. Anything beyond that would depend on the staff in question, since they can be enchanted in other ways.

Learning to use one would basically require her to transfer the focus/mental habits associated with wand movements to new movements with a staff.