TL;DR at the bottom
I'd like to point out several flaws in your argument. First, starting with your scalings. Her Q is not 480 (+90% AP) and it's unfair to claim that it's by default a triple proc, AND that it's unbalanced just because you got cc'd around a low health minion or ally being in a very close proximity of them and got hit by all three procs. Her Q is 80 / 125 / 170 / 215 / 260 (+ 50% AP) on the first hit, and requires that an enemy die for the second proc to kick in, and another enemy to die for the third proc to kick in. The second and third proc deal 40 / 60 / 80 / 100 / 120 (+ 20% AP) each. If you get stunned by Viktor's E, unless you're right next to an ally minion or champion that is going to die from the 260 (+50% AP) proc, you are not going to get hit by all three procs. It is balanced around the fact that there is a significant amount of counterplay behind the second and third proc. The Neeko is rewarded for not only landing the channeled first hit, but also for landing it in a matter that it kills an enemy minion or champion while hitting a second target. She is then rewarded for a second channeled proc in the same location as the first one was. She is then further rewarded for landing it in a matter that it kills two enemy champions or minions, for a third channeled proc, once again in the same location. The enemy has plenty of counterplay around this. First, paying attention to positioning will prevent them from being around a dying ally, similar to spreading so Malphite doesn't ult 5 people but in a much smaller proximity and with no knockup. Only damage. Which means you visibly see the skillshot coming and move away from it as well. If they by chance are around a low health minion or champion, they then have a full second to move out of where the ability originally hit. If somehow the third proc manages to go of, they have yet another second to move away. Unless you are Morgana binded right next to two low health minions, you are not going to get hit by all three. You have a higher chance of dying to the five enemy champions coming at you than the third proc even managing to go off before you die if you get Morgana binded.
Next, every mage and ap assassin besides Zoe and Viktor have damage on every ability. When a champion doesn't have damage on every ability, it's compensated in other areas. Viktor gets an item that lets his Q deal damage a second time and increases the strength of other abilities. Zoe is compensated by being rewarded for dealing insane amounts of burst damage if she lands her E (which is incredibly hard to land against smart enemies), and that damage is even punished by giving her low mobility, which is further compensated by giving her mobility if she's in close range for a long period of time.
Before I go on:
[{quoted}](name=Radiant Wukong,realm=NA,application-id=3ErqAdtq,discussion-id=m8EtAyM6,comment-id=,timestamp=2018-11-29T00:55:40.905+0000)
Don't compare her to Zoe, they're nothing alike besides both being colorful and cheery.
I'm sorry? They're both AP. They're both burst mage assassins. They both have low mobility that is compensated on their W. Just because their playstyles aren't the same doesn't mean they don't have aspects that line up with Riot's balancing philosophy.
Now, to continue, notice this pattern in Zoe specifically. Where she is strong in damage, she is punished in other areas, but given mechanics that a skilled player can pinch themself out of being punished. Let's look at Viktor: He has low mobility that is compensated for by giving him a form of defense and mobility in close range (his W). His shield is the defensive by default, which is great for early game! However, as the game goes on that small shield isn't going to protect him very well from melee assassins. So, he's given an augment that increases his mobility when casting his W. Because his passive and E don't deal damage, he is compensated by having augments that enhance his gameplay and provide bonus damage.
Both Zoe and Viktor's damage are fair and balanced because they don't have damage on all of their abilities, and their damaging abilities are skillshots. The player is rewarded for landing their one or two high damage abilities, with minor damage added to their Ws; Zoe's as a passive, Viktor's on his autoattack. The enemy is able to punish the fact that both of their damaging abilities are skillshots by anticipating where the Viktor or Zoe will aim their skillshot, then take advantage of their long cooldowns.
So let's look at Neeko. She has no damage on her passive, low damage on her W, and moderate damage on her E. Her scalings specifically are:
W - 50 / 80 / 110 / 140 / 170 (+ 60% AP)
E - 80 / 115 / 150 / 185 / 220 (+ 40% AP)
Her W is low damage, just like Zoe and Viktor's. You have to land three auto attacks in order to deal such a small amount of damage. She is a mage, which already has a low attack speed. Albeit high elo mages do autoattack between abilities, 50% of the community is in Silver, meaning most of them aren't going to aa-Q-aa-E-aa to get her passive off. Even then, because of her low attack speed there is a lot of counterplay in bursting her before she even manages to get the third auto off, or punishing her for autoing if she tries to use it to initiate by trading damage. If she wastes her Q to trade back, she loses the pressure of getting her third auto off in lane because now she can't initiate since her Q is on cd.
Her E deals okay damage, but it's not nearly as large as her Q because of the fact that it's a crowd control effect. Also, it's a linear skillshot that moves at a small speed unless it hits something, similar to Zoe's bubble except Zoe's bubble doesn't get a speed bonus or move through units. Instead, Zoe's bubble is compensated by gaining a range increase through terrain. So, Neeko's linear skillshot cc is compensated by increasing in speed as it moves through units. The enemy can dodge it.
Lastly, her ult is a 1.25 second channel that enemies can see unless she is invisible. She is only shielded for .75 seconds, during the channel, about 1/3rd the duration of Viktor's shield (2.5), and for 50 / 80 / 110 (+ 50% AP), which is a tad larger than Viktor's shield, 8% of his maximum mana (+ 15% AP). At level 6, Viktor's shield is roughly 60 using an AP ratio of 100 (20+Blasting Wand+Lost Chapter), Neeko's being 100 with the same basis. She cannot take action during this shield. Neeko then deals 250 / 425 / 650 (+ 130% AP) in the area and stuns all enemies for 1.25 seconds. Analyzing this, her entire ult requires her to be in very close range of the enemies as a squishy mage. Her shield is meant to protect her for half of the channel (.75/1.25), meaning you only have to burst through about 100 shield at level 6 and she's unprotected for the rest of the channel. The enemy can see the Neeko coming at them and poke her down from a range, allowing her to be cc'd or bursted when she gets in close range to land the ult. If she is cc'd while the enemy is also cc'd, she cannot get off her damage after the ult ends. Because the enemy can see her channeling it, in close range, and has a full 1.25 seconds to react, they can throw a Panth W or Viktor E, or any form of cc that lasts longer than 1.25 seconds, and she cannot get her damage off during her ult. She is compensated by being allowed to channel it from stealth, and rewarded by it dealing a large amount of damage and ccing if she successfully lands the ult without dying. Overall, this is a high-risk high-reward ultimate that is very easy to punish but very dangerous if the Neeko is skilled. Similar to Zoe's ultimate E/Q combo.
#TL;DR
All in all, Neeko is a very balanced champion. Her damage is only on two abilities, not including her ultimate, and are all skillshots, which is compensated by making those abilities deal a large amount of damage. This is the reward for being skilled at Neeko that is also highly punishable and can be outplayed. Her ultimate puts her in a lot of danger with many ways for enemies to play around it. If the Neeko manages to get into melee range as a squishy without dying, she is permitted to deal a lot of damage and cc the whole team, and if she is not punished by enemy cc, she is able to get off her full combo. Her ult is compensated by being allowed to channel from stealth, and by giving her a mediocre shield. She is a champion that has a lot of counterplay and will require the player to be smart as well as get the hang of the champion to fully utilize her kit. She is in no way unbalanced and shouldn't be asking for nerfs before there's even enough data on her.
#Neeko's Stats
http://leagueoflegends.wikia.com/wiki/Neeko