Normally i play passive until level 6 but i do harass with my q since it has a lof of range and strong early,mid and late game damage

Pros: Great for teamfights, strong, great roams, amazing ult
Cons: easy to counter, melee ranged ap, long eary game cool downs

Hybrid pen is good for diana since to use her passive you have to auto attack, early trading is mosty auto attacks unless you play passive until level 6. Armor is good against ad champs and mr for ap champs.

Normally i run 21/9 but in special occasions i run 9/21 or even 21/0/9 for the extra mana regen and cdr

my normal combo is q>r>w>e>r