Observations on some specific champion match-ups

I've been on the long and hard road of trying to master how to play Yasuo top-lane fighter against the various champions that typically are fought against when top. And yes, I've failed plenty, and I'm still no pro, but I've been getting better... I think? That being said, there's just a few things I've noticed that seem worthy of note:

1: VS Top lane: Poppy seems to be a good counter to Yasuo, and I can respect that. However, when level 6 comes around and Poppy gets her ult, things seem to become rather beyond skill entirely. I'm not asking for a nerf, but I'd like to recommend having Poppy's ult be considered as a debuff on her target, and open up some room to fight back by letting Quicksilver Sash/Mercurial Scimitar cancel Poppy's ult with the [UNIQUE Active - Quicksilver]. How do you (as in everyone) think that would do?

2: VS Top Lane: Don't worry; no nerf requests here either. (I've successfully outplayed a Teemo as Yasuo at least once) The only thing that I wanted to mention here is that it seems like Teemo's [Q] - Blinding Dart has a tendancy to pass through Yasuo's [W] - Wind Wall if the Wind Wall is used as the Blinding Dart is incoming, as opposed to when Wind Wall is used right before blinding dart is fired (as when correctly anticipating when Teemo's about to use it). I suppose it's not too great of an issue since Yasuo's [Q] - Steel Tempest can't miss anyways.

3: Yasuo in general: The only thing I have to say here is that I think Yasuo should be un-targetable and invulnerable during his ult, more like ; It's just so depressing when you ult successfully, but then die immediately after the "blink"/"dash" to your target. :(

4: Kat in comparison to other champions: even before the nerfs to Kat, she's been easily countered by people playing , , , and so long as they know what they're doing. And with the addition of Ekko, Kat seems a bit over-nerfed to me at this point. but that's just my opinion. Yes, Kat can seem OP when fed, but playing wisely usually is enough to prevent that from happening. Kat doesn't come off of the summoner's platform fed & OP when the match starts; and Kat is always vulnerable to CCs, even when fed.

So, any opinions, people? :)