If you want to nerf Zoe AND make her less frustrating to play against...

Just give her W a static cooldown, like 2/3 seconds. This way she can’t kill you because she got 3 ignites in a row and you have room to deal with her mindlessly, zero cost W spam.

Changing the spell’s damage won’t change how awful it feels to get killed through empowered autos and active effects with no cooldown and mana cost. And I like to play Zoe so my opinion is not biased at all.