Caitlyn makes no sense!
Let's just get this out of the way- This is not a balancing change. It will effect gameplay, but just not for balancing reasons.
Sniper Rifles are generally long range, slow guns. But in most Caitlyn builds I see, there is Statikk Shiv, Runnan's Hurricane, Rapidfire Cannon, ect. I think that Caitlyn's passive should just have something added on that lowers her attack speed but increases her attack damage.
It could either be "Caitlyn has X% reduced attack speed and X% increased attack damage." or it could just have attack speed reliant items like the ones listed above be less effective (at least the attack speed part) so they wil have less gold value, forcing her to buy other things.
All in all, I want Caitlyn to have less attack speed and more attack damage, just because it would make more sense. (Jhin orives that this would work on an ADC)