General list of changes that I feel like would improve the game

Hello, I am a veteran player and I've always had interest in balancing champions/and coming up with concepts for reworks. I'm not the best, but I feel like over the years I've had some pretty good ideas for how to change up the game in a way that wouldn't be too overwhelming. I'll be focusing mainly on a few champions.

Kog'Maw - Kog'Maw's not looking too hot right now. He has a 46% winrate, relies on his team to much, and the mobility creep has treated him the worst out of all champions. Games are shorter now, there's too much burst in this game and ADCs are super weak in the early game. A bump in Kog'Maw's abysmal base stats would go a long way (more base mr/ad). However, what I really think would be a great buff would be to add the "grounded" effect to Kog'Maw's E - Void Ooze. It's so perfect thematically I can't believe they haven't done it yet. Just look at the icon for the ability. Not only is it perfect for the theme, but it's a direct counter to mobility and assassins that would otherwise dash to the back lines and kill him instantly. It would also increase the playmaking potential of the champion. A well timed E could punish an Assassin or prevent champions from simply dashing away from your passive. This is my favorite suggestion and I really hope it's added to the game. Something so little that would help the champion in so many ways.

Zoe - This is a hard one to balance but the rework they are considering goes in the wrong way. Removing Zoe's E puddle would remove something from the champion that makes it unique. The problem with it is that it has a large hitbox and lasts way too long. If I were to do something I would decrease the bubble size and lower the duration to 1 second. As for compensation I would lower the cooldown on her Q, but lower the damage slightly. I would also increase the sleep time to 3 seconds (the sleep effect isn't really that bad, it's interrupted by any sort of damage and has a delay before it happens). But in return tenacity should have an effect on sleep. Removing the movement speed she gets from spell theft would also be a good thing to look into, since she's going to get flash most of the time from her w the mobility is just overkill.

Ornn - His ult is so powerful that it overshadows the rest of his kit. Lowering the speed of the ram and slow would give enemies more time to react, thus making it not as game changing in higher levels of play. Return the unstoppable effect on his W and lower the buffer time when he misses his E.

Diana - This champion has alot of missing potential. Her E should do damage (it would help Jungle Diana be viable) and maybe a microstun at the tip of her Q. Her skills just feel so bland.

Hecarim - This champion is hit or miss. His W has no synergy with the rest of his kit and I think it should steal movement speed, at the cost of lowering it's sustain. His E can also be more unique, it's used for escaping and or one shotting someone. I think it should work a little like righteous glory; where you gain movement speed towards enemies (and maybe monsters) but it isn't really used as an escape.

Thoughts?