With regards to jumping vs stepping, I have a few thoughts.
First, I will describe my boat to provide context. 35', double ender, relatively high freeboard, centre cockpit with canvas enclosure, so a bit of a scramble to get out to handle lines, I have bulwarks, which means all lines are lead through fairleads.
My crew is generally single handed or any combination of me plus any or all of me, my wife, my two 1/2 year old and my dog. Sometimes I drive, sometimes my wife drives, she insists on getting docking opportunities, I think mostly because she enjoys it.
My rules are any one outside the cockpit wears a life jacket (myself included), children and dogs wear life jackets even inside the cockpit. Nobody steps off the boat until at least one line is secured, usually by means of lassoing a cleat and doubling the line back, or in the case of a ring, fence or railing, reaching around the ring and feeding the line back to the boat. We are able to follow this rule probably %95, of the time, occasionally we are forced to break our own rule.
As mentioned, my boat is centre cockpit, double ender, so bringing the stern to the dock first isn't effective. I solve this issue, by landing (bringing the boat to the dock) just aft of midships, since I'm usually single handed, this is kind of a must, I don't like being far from my engine controls.
If somebody must step off, I would say it comes down to body mechanics. The skipper brings the boat to the dock, the crew steps off. By stepping I would say, at no time should their centre of gravity be fully over the water. As mentioned above, if you are pushing off with enough force to become airborne, you aren't stepping.
Hopefully this makes sense.