There are so many ways to cut us the way, many... Specially the ones that cut our run and see us run slowly to our salvation (or actually damnation).
Yasuo needs to overcome the speed limitations and minimize risks, that is, like Samurai during Bakufu he needs to be able to run and minimize negative effects during his running away.

Yasuo is not Nasus that can withstand many hits, neither Yi who can recover health in the middle of a fight or avoid being targetted or run like a gacel. So you need to think of ways to overcome that situation.

I put guardian angel because you'll see many duels ending with a slight difference of health and you'd love to come back to take revenge. Despite that, I'd recommend also the Phantom Dancer... Not because of the speed but because the fact you can run between the minions without worrying about speed or getting caught.

Runes I've found that are really easy to divide with Yasuo.
Life stealing, armor, magic resistance and attack speed.

So if you're willing to invest some points go for the full defense and speed package.