Are PTC resettable fuses fast enough to protect from shorts?
I believe at 20-25A time for a PTC to trip is significantly less than 0.1s.  From what I recall, 0.1s is generally the time to trip at 7A or less.  In either case, voltage regulators usually have over current protection, and for the most part, a ferrite bead is just a wire.  You should be fine for the most part unless you have some real sensitive components.