From your description I would say that the rafters are restrained at the bottom end by a horizontal member (bottom chord) and are in compression at the top. In that case the ridge does little for the main structure of the roof beyond preventing deflection of the rafters at the peak.
Or..long story short, you have trusses, which are more than adequate for the span.
But, don't take my word for it, take an enginers word (and stamp) for it.
As for the fasteners, typically some type of mechanical fastener is used in this location and if our predecessors had access to the mechanically produced (read cheap) fasteners we have now, they would most likely have made use of them in this location. Spend the extra money your framer would cost here on something fun.
Re screws vs. nails: Nails actually have more shear value at the same shank size and near the end of the member either screws or nails would require pre-drilling. I doubt however that shear is an issue here and inasmuch as it’s all hidden would be inclined to leave it to the framer preference.
