I'll start:
Viper: Just make her walls and smoke retractable like KJ and Cypher tools, that way she FINALLY play retake without having to sacrifice not using her tools earlier in the round, would also put her in the same ballpark as Brim when it comes to flexibility imo. A quality of life could be her being able to walk on her mollies with no dmg, but this one isn't really necessary imo.

Yoru: He's so fucking loud. It's not just that, but you can clearly tell where he is based on the sound of his utility. Whereas with Omen you can hear him teleport, but you won't know where exactly unless you're very close to him. But with yoru you can't fake a tp and you have to mask it with both of your flashes, steps and your team's utility. It's honestly just not viable to use the tp in any way that isn't as a rotation tool or in a similar manner as you'd use phoenix's ult. And maybe that's the intent and we're playing him wrong, but even if you play him as "intended" he's just not that useful. His steps are fine imo, not that useful but I do think they're underused in general and players aren't using them to their full capacity. His flashes are fine too imho.

Skye: She's fine, her ult is just too weak imo. She can't really play for herself but she doesn't have to, her healing is strong asf and so are her flashes, it's fine that it takes skill to play her correctly, but her ult is just not all that imho, more often than not it gets destroyed and you don't get to play off of it. How to make it better? Idk it's tricky. Increase movement speed maybe? Or maybe make it tank a lil more? I don't want it to be annoying to fight against.