Infinity -> Bloodthirster items so fast? hmmm.. and that late game malady+Zeal (probably a Phantom later but i am not sure...)?
Well at least you have your bloodrazor :)
Get those runes done... we are not lvl 10 here :)

The link you provided is broken and you have no idea about BBCode i think.
the link should contain only the end part: PwjmAK3flY.
I'll give a hand and post it: Play Video
His jungling video is very old tho.

About ulti. If done properly and you focus on getting good items its quite doable to kill a squishy from 50% health just with your ultimate.
It all depends on what you focus, this guide focuses too much on "white damage" that is why.

Masteries... those def masteries are useless... Lethality (even with your low crit) will be way better than Strenght of SPirit... And mana regen from utilities would serve you better than those def masteries if you dont jungle. HS spam is quite mana uneffective without it.

This is a good build for a lanning Warwick but i don't understand you're runes, why get lesser ones? For your items why don't you get any magic resistance like Wits end. Also, I don;t understand for your're masteries why you go for health in your defense, why not utility so u max out your're experience. But other than that this is how i started playing Warwick when i was lanning. Good job on your first guide.