You might want to look at just how long Yi's CD is for Alpha Strike. Even with maxed AS his Alpha still takes a while to round back to 0 after using it, and let's not mention he has to be in the enemy's faces to AA like a madman for that to happen. (Also Yi players also do not stack CDR, because he's intentionally designed that it's not worth to stack it, and so players are pretty much pushed to use the AS related builds, which in return makes it so CDR stacking won't be a thing for Q, and the only factors will be his AA and R-passive)
Yi can only Alpha "every two seconds" when he's downing your teammates 1 by 1 and use the refresh attached on his ulti to continuously use Q. So your suggestions mean a couple things:
- You don't believe Yi should be rewarded for getting to his mid-late game as a hypercarry, nor do you believe he should be rewarded for snowballing as a hypercarry.
- Your changes touch on nothing that's actually relevant to the topic you're trying to tackle, whether or not it's a real issue worthy to be tackled. Because his CDR per hit is only a minor player, his R's passive refresh is what POTENTIALLY allows Yi to use Q that often, IF he can manage to continuously score takedowns in combat. Again, refer to point #1.
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Also, making Alpha a dash will literally destroy him. That untargetability is the center balance point for him, that makes his entire existence and design, and the fact he's intentionally made to be over-reliant on Q, work. It's there so that it justifies having him being squishy as all hell despite being a melee character, that he has literally ZERO CC and utility of any sort, high base CD for Q, Q being intentionally overloaded so he has to choose from using it as either gapcloser or trading tool or dps or situational escape at any given moment, and having no real escapes of his own (I mentioned situational escape, because Q offers "escape" ONLY in the form of either running into other but hopefully lesser danger (and also limited because it needs both a unit that is also hostile AND nearby) or you have to pray you kill the enemy so you can leave with head still on the neck), being stuck in a long animation for Q that you have little to no agency over, etc. All of those are tied to a central balance point of untargetability in a delicate manner as the 1 big plus that balances all of the big and small dead weights of Yi's design.
And if you just take untargetability away, well, Yi literally becomes trash. And he already is anyway, or at least we're talking about elo where it has any semblance of skill, so imagine where he will be if this change were to go through.