Fizz's E and R should be tweaked

So before anyone points it out yes i just played game vs fizz that snowballed and i'm a silver scrub. Also not native at English so my grammar is pretty bad.(Also i say "so" a lot sorry about that)

Okay so to my salty whining, i don't think that fizz is that broken in lane early but hes Playful / Trickster shouldn't be so versatile. So what so i mean whit this? It has; initial movement, invulnerability, Good damage, Decent Slow (if second cast isn't used) and final movement.

Playful / Trickster: Invulnerability: So i'm not sure how i would do for the invulnerability, maybe cc invulnerability? And then buff its base damage early, increase the range, giving it a smaller slow if recasted, or just lower the cooldown.

edit: Drakelorg made a good point that i forgot. I think that it still should remove debuff (not sure if right word) like zed ult and ignite or maybe be invulnerability to them

Damage: Late game with full build you deal a bit under 1000 AP damage (if target had 0 mr) and you also have 35% magic pen. I think it should deal a bit less but maybe scale with targets missing health for more assassin like gameplay or max health to make fizz a better tank killer.

I don't think that slow and mobility of it is problematic

Chum the Waters:

I think that this ability is a bit too strong in team fights as it isn't that hard to pull of the biggest shark. I do like it in lane as it reward hitting a difficult skill shot if you get the biggest shark an punishes easy point blank ult. I don't know how to balance this for 1v1s and team fights correctly but maybe lover the cc it offers by lowering slow or knock up duration. Or lower its damage based on how many enemies are hit?

Regards, a salty silver player