HELP KHAZIX

I love khazix and I put way too many matches into this champ trying to get good at someone who can get counterplayed soooo easily. I think the cooldown between each invisibilty of his ultimate should ATLEAST get cut in half because by the time you are visible, the enemy team can easily kill you before you go invisible again. Also I think his passive slow should be higher because he has 0 stuns/snares and therefore if there is a leblanc/zed mid you have no chance of killing them unless your mid laner sets it up very well. Also is late game is super trash right now, since his damage is supposed to be dealt in small bursts that cant do sht against a champion with 1 defensive item later on. Also maybe increase his leap speed, because it gives his opponent much less time to react. I get that you made khazix to be similar to Rengar cause he is his hunter-enemy, but right now there is NO REASON why ANYONE in their right mind would pick Khazix over Rengar, who has much more damage, a fricken stun, and can go invisible for 13 seconds late game. Also his isolation needs to be looked at because right now, without it, his q is like an auto with a bit more damage when the target is not isolated. Its just so sad when a champion depends soly on his opponents mistakes. Also I feel like khazix's evolution abilities need to be buffed. Maybe make the first ability that you evolve be much stronger than the other ones. This will make khazix much more adaptable to the game that he is in. For example if I evolve my claws first, then every q does isolation damage, but if I evolve my e second then the leap range isnt as big. But if you evolve your leap first than it can be something like a zac e, and slow enemies hit, but then make the q like it is now (more damage when isolated). And I have no idea what his w could be, since I hardly ever evolve it.