I've also heard that jumping can be pretty good as an attack, so that last idea could work.
Jumping is rather hilarious at the moment, and actually one of the few ways you can take on a necromancer tower - albeit at the constant risk of instasplatting if any of the dozens of attacks you receive hit you.
It's very useful for one specific purpose though - getting your passed-out companions out of trouble, since they won't dodge your jump and are thus catapulted away in the direction you jumped in.
Actually, having done some testing with a peasant character, jumping is absolutely suicidal unless your opponent is prone or knocked out. Seriously, you will die. Also it seems you can't actually attack while in the air (at least I've never had the option to).
Think of jumping as a movement saver/shortcut/distance maintainer. As in:1.) Leading someone outside of their lair
-Get their attention. Then you jump backwards towards the exit which allows you to cover more distance per 10 instances/a full turn. Were you to move without jumping, even with speed set to sprint, a fast opponent will have closed the distance with your back turned to them. Jumping maintains distance when exiting.
2.) Positioning
-Fighting mobs outdoors. To help with kiting (stringing the line of attackers out so they are not crowded around you), you can opt to jump in cases where dodge away won't give you a preferred direction. Jumping here can also help you to escape a mob if the environment helps you, whether it's because you jump into a river or because the terrain obscures line of vision.
-Fighting a solitary opponent who is faster (has better stats than you). Likely, in this case you are opting to multi-attack a quick attack + dodge away outdoors. Whether it's because now with space between the two of you, you'd like to reposition because of environment (river up ahead) or because your preferred dodge away direction is not being offered, jumping helps maintain distance and change direction.
-Fighting inside a lair. Like a lot of things, it's about the stat comparison, and the most important stat comparison seems to be about speed. You can change your position in an indoor lair combat (say versus the slow cyclops, giant or ettin) by jumping. If you're fighting something faster in a lair, well, there are other problems besides jumping's now deadly consequences if used for anything but exiting the lair.
Just to repeat, the above ideas regarding jumping are confined to the non-powerleveler who is soloing all fights. Companions in many of these situations will serve as meatshields, intentionally or not. My use of jumping is defensive and movement oriented.