Could Janna theoretically be an auto-attack based champion?
I'm wondering if Janna could be played effectively as an early game/mid game auto attack based champion, with her AP scalings, in combination with items like Guinsoo, Nashor, other AP items, and her Passive, which increases the damage she gives out for her autoattacks, while building Ardent Censer for her actual ADC, I'm wondering if Janna could serve to provide both utility and damage through autoattacks at the expense of her total safety in the back line. She still has a Q and R for self peel, she has W for slows, and she has an E for an attack damage steroid. Of course this isn't optimal, as Janna is supposed to be focused on defending the ADC, but would this be a nice alternative for support mains who also play ADC, who are stuck with autofilled ADCs?
, and get to a point where a single auto attack does 900+ damage. I've had one duel a Jhin to death.
or 
and
is not effective at all. One can be replaced by another.
You won't be powerful enough to deal damage constantly neither you will be able to burst, neither you will provide good enough utlity due to absence of such items.
I suggest you switch to champs like
to carry the game
Or AP
to deal both damage and provide basic utlity.