Hallo,
I'm an unimportant silver three... You've no real reason to listen to me, but i do play a large amount of off-meta/weird build paths and champions. As such, i tend to often find myself stretching champions strengths to the limit...and i'd just like to say: full ad diana stretches her...hybrid fits her kit very fluidly.
Good luck with it :D

Hybrid diana:
pros;
-Tanky mid/late
-Gunblade active provides a bit of extra chase/disengage
-Splitpushes/sieges/pushes like crazy(your passive damages turret)
Cons;
-Not as much cc as most tops
-Item reliant
-weak until six in most matchups.
AP diana mid:
pros;
-health bar? nah its gone.
-great roams bot post six
-Hypercarry
Cons;
-no escape
-weakish in teamfights
-countered by cc
-squishy

So, your general combo if a melee champ comes to aa trade with you is: q-aa-w-aa(until they back off)-e-aa(untill your passive procs or you fear minions)
Your all-in/post six combo is: hit q-r-aa-w-aa(till they back off)-e-aa-q-r-repeat
Remember that Diana's e is technically a knock-up, and combine that with her hybrid top, she works wonderfully with yasuo.

Try to last hit multiple minions with your passive, and be wary of it if you dont want to push.

USE THEM