Ive seen better builds on Ultimate Bravery

Yes, I know. That's why I said this, "In team fights that are equal in numbers or when you're outnumbered, it's best to just constantly spam your minions on top of the other team, but do not charge in. Wait either for at least a few of your team mates to start fighting or for the other team's health to go low before you start meleeing the enemies." As with any squishy, you want to be careful in team fights. If you're careful to stay alive and get a decent amount of feed, this build will work. I guess you could say its biggest flaw is how careful you have to be and how much skill it requires to be really successful.

Yorick is getting a pretty hefty buff too though, so everything should go a lot better. He'll be able to survive a bit better and his abilities are getting pretty hefty buffs, so he'll kill a lot faster.

edit - I'm editing out one of the Bloodthirsters for a Frozen Mallet. Extra health for survivability and the minions + a slow is definitely worth it imo and would be more helpful than another Bloodthirster, especially when you already will have two.

The only problem with it is not getting fed. Like you said, it's true that you can dish out a ton of damage, however your only survivablility comes from your-pregame runes and masteries. If you don't get fed, you're in for a game in which Omen of Famine doesn't give you enough life-steal and you die in almost every team fight. I like getting kills, but I consider the true success to be outplaying people and killing them without dying yourself. What's the use of 99 kills if you have 160 deaths? other than that, it's pretty good.