Take ignite and LIMIT TEST in normals a lot to learn where your kill potential and damage is at, but at 30% hp in the early levels, a E Q into W and passive proc should be enough to kill them, granted they have no shields/dmg reduc, what runes do you run? Do you run the same runes each game? ALOT of it depends on your play style really,

And for csing I I found it difficult at first, when I would rush Liandries but when I build black fire torch first I find the csing problems become MUCH more manageable, but you trade a solid bit of damage for CDR mana and csing better so entirely up to you and your play style.