Can Kalista be given a smaller amount of damage in the early game?

I've always disliked Kalista and it's for a few main reasons. Mostly her high damage in the early game.

Part of this comes from her W passive with deals 12/14/16/18/20% of the target's maximum health as magic damage. And early game most champions will have enough MR for about 20-30% resistance from magic damage, with the passive requiring two auto attacks for it to proc, it adds some physical damage that will get close to 11-14% (depending on the support's base AD) of the targets maximum from the total damage of the passive, which is pretty high early in the game, and gets even stronger late game. It would be much easier to deal with this if the percentages were lowered by about 2% each rank, lowering the total damage to be not so staggering.

(Warning, Math)

Another is her E. The base damages are fine. However, the ratios are a little much, seeing as the ability can infinitely stack. Let's say you get about 6 auto attacks on an enemy then use Rend, it would deal 70 (+160% AD) rank 1. Now max rank, the same amount of auto attacks would be 220 (+ 210% AD) Which is quite high. Going from her standard build, let's say she is level 15 with Runaan's Hurricane, Bloodthirster, Berserker's Grieves, Infinity Edge, and a dagger to start on statikk or phantom dancer. Her AD would be about 286 or 298 with first dragon buff. Her AS would be about 1.828 or 1 auto attack every 0.547 seconds. In a teamfight that lasts 6 seconds, she could get off about 11 auto attacks. Making the damage from Rend (assuming maximum rank) 380 (+ 360% AD) which would equate to 1409.6 or 1452.8 with the ability alone, which would be on about 3 people with the Runaan's Hurricane. Including auto attacks themselves, it would be an additional 3885.2 (this is including the critical chance from Infinity Edge and bonus damage per auto with Runaan's Hurricane) or 4111.712 (with 1st dragon buff) on the main target. Side targets would be dealt 1997.6 or 2110.856 additional damage. This makes for a total of 5294.8 or 5564.512 on the main target and 3407.2 or 3563.656 on the side targets, with a 45% slow for 2 seconds after the ability is cast. Even with 100 armor (50% resistance) this ability would kill a majority of champions outside of the extremely heavy tanks, and this was only in a 6 second fight, not including damage from allies, Kalista's Q, or W passive.

Note the ability is only 40 mana, and refunds mana and cooldown on kill with the ability, making it a simple but highly effective harrass/farm tool. The only ability from other ADCs overcome Rend is Lucian's Ultimate, with at least half of the shots hitting a single target. Don't forget, this costs 100 mana and locks Lucian in a direction to aim, making it quite dodgable, and has a 100 second cooldown at rank 2 (where it would be at level 15). No other ADC ability comes close to this. Even though it does take time, it doesn't seem all too fair to have an ability which can stack up for damage to the point enemy in the game, including baron, could be dealt 100% hp with it.

It wouldn't be nearly as bad if it weren't for Kalista's safety against skillshots with her passive. However; her passive is her identity so that should not be changed, it is the whole reason as to why she can be identified as one of the top tier ADCs for kiting. Rather, there are a few ways to tweak Rend that would make it more reasonable to allow her safety, without keeping her high damage. (these are separate ideas that would not be put together).

1. Add a cap to it, probably 8, it would still be a high damage ability but wouldn't be an ability that makes the opposer feel as though nothing could be done about it.
2. Remove the Mana refund, increase cost to 60 and keep the cooldown refund. Makes the ability spammable but requires management of mana. With the current refund it allows completely free and fast wave clear and damage nukes on enemies (tip: with runaans have some stacks on minions, will kill them and give the refund).
3. Remove the AD Ratio on all spears after the first, it only takes 4 auto attacks to make the ability exceed 100% AD ratio, which is quite high. Can increase the AD ratio on the first spear to adjust.

Edit: Sorry, I know title says early game but I also went into a lot of late game :x