Stamina drop rates and such should also depend on the speed you\'re going at, not everyone wants to run all the time, when their stamina is at 100%
I recall it\'s been stated elsewhere, but someone suggested different speeds, walking, jogging, running and sprinting instead of just running or walking.
For example, one day I may want to jog all the way to Akkaio instead of running, and the next I could walk back, but suddenly need to sprint away from an approaching pack of Ulbernaults while I walk down the road.
What I would suggest is a combination between what has been suggested here and the other suggestion. That way, we\'d have fairly good control over the speeds we go at. ^^
Jumping, eh... It could benefit from good stamina, but I\'m thinking that jumping would be mostly based on other skills, ie. a jumping skill. Running is displacing yourself horizontally, or at least on a \'flat\' plane, while jumping is displacing yourself vertically, so to speak.
After all, a good runner is not necessairly a good jumper.