Obviously we know Lucian is one of Riot's problem children. I play a lot of ADC, and I think a small change to Lucian could make a world of difference. Currently when Lucian casts a spell, he gets his lightslinger passive for 6 seconds. I think that's a lot of time that he can just hold it and still get his cooldown on his E. I'm not saying he needs it to instantly shoot his passive off, but maybe reducing it to 3 seconds will make a difference. If he's chasing with his E, and he can't get the lightslinger off, it will reduce his mobility.
Just an idea!