Yup; https://en.m.wikipedia.org/wiki/Reduced_vertical_separation_minima https://en.m.wikipedia.org/wiki/Reduced_vertical_separation_... A plane can ascend/desc

Yup; https://en.m.wikipedia.org/wiki/Reduced_vertical_separation_minima https://en.m.wikipedia.org/wiki/Reduced_vertical_separation_... A plane can ascend/descend fast, but generally stick to either 500 or 1000ft/min.