Yasuo can easily push the lane early. So easily in fact that its hard for him to farm lane because it is almost always pushed up under his opponent's turret. His E is completely useless without neutral monsters, minions, or champs to which he can dash. But this does let him roam.
His shield is for all intents and purposes, non-existent. It is easily procced and takes forever to recharge. His Windwall is also on a very long cooldown. But that at least blocks all projectiles.
Champs like Heimer and Karthus take a big huge dump right in his face because of their endless poke and ranged attacks. Annie's stun absolutely obliterates him. Any hard CC obliterates Yasuo. Doing good magic damage forces him to build something other than his core SS and IE items.
Don't let Yasuo feed. He is extremely item dependent. Harass, harass, and harass some more. If you keep him off the farm through either harass or freezing the lane right at your turret, he will rapidly fall behind. When he roams because lane is pushed, ping MIA repeatedly. If he is out doing scuttle crab, he is screwing his jungler of gold. If he is taking his chickens, he is screwing his jungler of gold and the smite buff. If he is taking your chickens, you need to do something about it.