A trial of Prednisone can be as short as 5-7 days...and most can tell if it will help during this time. Also, this short period means no tapering off over a long period (anything over this can require a taper).

I have seen doctors use anything from a 40 mg taper to 60 mg taper (and they drop 10-20 mg every day or 2 days). You'll have to see what your doctor thinks is best.

Yes, the morphology check the condition of the fibers...for swelling, segmentation, etc.