Doran's Blade and 1 pot to start. I guess if youre facing someone that harasses well you could go with a longsword and 3 pots. I like the red elixir and 3 pots as another option too.
The brutalizer has cdr, armor pen, and more dmg. It's really nice to have early on. You can get boots after that. I just don't like buying boots before I complete a damage item. Your shock blast and hyper charge harass should be enough to keep away any incoming melees off of you.
You're right about vision control. Everyone should be warding. I didn't mean the fact that Yasuo didn't ward wouldn't have helped, because it definitely would have. A lot of the time when someone gets behind it is because of crappy warding. I've played in plenty of matches where the losing team isn't warding and just lets the winning team take over their jungle.
A tip for getting those two cs when they're away from each other. You can auto one and then quickly shoot a shock blast at the other right after you fire your auto.
Yea the more you play the more you'll be in certain situations like kha and malph diving you. Practice makes perfect