I don't think improving running means you will never lose. It just would mean that your characters will no longer be suicidal and fight to the death 100% of the time for fear of leaving transition points clustered with nasty suprises for others to see. And making the running speed and duration linked to stamina would make running much easier for monsters you dont want to fight at all and want to avoid, vs. having a bad day fighting some you expected to win against and being low on stamina, too beat up to run quick enough. In Gothic 3 if you tried to run with low stamina, you were often cut down by foes or beaten down intot he dirt. If however you were exploring a cave at a walking pace and saw a dragon around the corner... RUN RUN RUN! Often times I'd be running from things that were still napping and couldn't even see me. That's a good difference between the two I think. You could also use the terrain a bit, duck behind houses to avoid arrows or fireballs, one time I was running from a group of trolls and did a sprinting leap off a cliff into a lake below! now that was fun, I felt more pumped about that escape than most of my victories in battle.
In game items like choking powers, flashvials, blinding peppers, smokebombs, caltrops and the like would be useful to help failitate some rather batman-like escapes. OR for enemies to hinder ours! And trust me, in a maze-like cavern system where a wrong turn leads between a rock and a hard place, running will not ALWAYS work! Even in the woods you risk sprinting into a den of angry badgers or the backside of a hungry bear, nasty suprises all around.