Attribute you missed from your list - invisibility?
Seriously though I think a hero needs continue to try and achieve no matter what the odds. E.G. If I saw a woman been attacked in the street by a man, I would try and stop it, as would a hero. If I saw a woman been attacked in the street by 50 men all with swords and guns a hero would try and stop it, me, I dont really know.
Also a hero doesnt need to succeed. If the above hero is a master in martial arts, has a bat cape and can turn invisible, fighting that one person won't be majorly difficult, but if the person that tries to stop it is old fairly infirm and only has one leg for example, they may well fail, but that doesnt make them any less heroic.
We sing the praises of hero's who succeed but many unsung hero's are just as heroic or even more so, because they try where they have less chance of success
Just my 2 cents
W